<?xml version="1.0" encoding="us-ascii" standalone="yes"?>
<!-- RRD ActiveDisclosure(SM) XBRL Linkbase Document - http://www.financial.rrd.com/ -->
<!-- Creation Date      : 2014-05-06T16:17:25.3878099+00:00 -->
<!-- Version            : 1.8.3.0 -->
<!-- Package ID         : BE4A5ED11FCF54C04749D658B3B90F6C-0000879407-001403 -->
<!-- Copyright (c) 2014 R. R. Donnelley & Sons Company. All Rights Reserved. -->
<linkbase xmlns="http://www.xbrl.org/2003/linkbase" xmlns:link="http://www.xbrl.org/2003/linkbase" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.xbrl.org/2003/linkbase http://www.xbrl.org/2003/xbrl-linkbase-2003-12-31.xsd">
  <roleRef roleURI="http://www.arrowheadresearch.com/20140331/role/TemplateLink" xlink:href="arwr-20140331.xsd#TemplateLink" xlink:type="simple" />
  <roleRef roleURI="http://www.arrowheadresearch.com/20140331/taxonomy/role/DocumentDocumentAndEntityInformation" xlink:href="arwr-20140331.xsd#Role_DocumentDocumentAndEntityInformation" xlink:type="simple" />
  <presentationLink xlink:type="extended" xlink:role="http://www.arrowheadresearch.com/20140331/taxonomy/role/DocumentDocumentAndEntityInformation">
    <loc xlink:href="http://xbrl.sec.gov/dei/2013/dei-2013-01-31.xsd#dei_EntityCommonStockSharesOutstanding" xlink:type="locator" xlink:label="dei_EntityCommonStockSharesOutstanding" />
    <loc xlink:href="http://xbrl.sec.gov/dei/2013/dei-2013-01-31.xsd#dei_EntityFilerCategory" xlink:type="locator" xlink:label="dei_EntityFilerCategory" />
    <loc xlink:href="http://xbrl.sec.gov/dei/2013/dei-2013-01-31.xsd#dei_CurrentFiscalYearEndDate" xlink:type="locator" xlink:label="dei_CurrentFiscalYearEndDate" />
    <loc xlink:href="http://xbrl.sec.gov/dei/2013/dei-2013-01-31.xsd#dei_EntityCentralIndexKey" xlink:type="locator" xlink:label="dei_EntityCentralIndexKey" />
    <loc xlink:href="http://xbrl.sec.gov/dei/2013/dei-2013-01-31.xsd#dei_EntityRegistrantName" xlink:type="locator" xlink:label="dei_EntityRegistrantName" />
    <loc xlink:href="http://xbrl.sec.gov/dei/2013/dei-2013-01-31.xsd#dei_TradingSymbol" xlink:type="locator" xlink:label="dei_TradingSymbol" />
    <loc xlink:href="http://xbrl.sec.gov/dei/2013/dei-2013-01-31.xsd#dei_DocumentFiscalPeriodFocus" xlink:type="locator" xlink:label="dei_DocumentFiscalPeriodFocus" />
    <loc xlink:href="http://xbrl.sec.gov/dei/2013/dei-2013-01-31.xsd#dei_DocumentFiscalYearFocus" xlink:type="locator" xlink:label="dei_DocumentFiscalYearFocus" />
    <loc xlink:href="http://xbrl.sec.gov/dei/2013/dei-2013-01-31.xsd#dei_DocumentPeriodEndDate" xlink:type="locator" xlink:label="dei_DocumentPeriodEndDate" />
    <loc xlink:href="http://xbrl.sec.gov/dei/2013/dei-2013-01-31.xsd#dei_AmendmentFlag" xlink:type="locator" xlink:label="dei_AmendmentFlag" />
    <loc xlink:href="http://xbrl.sec.gov/dei/2013/dei-2013-01-31.xsd#dei_DocumentType" xlink:type="locator" xlink:label="dei_DocumentType" />
    <loc xlink:href="arwr-20140331.xsd#arwr_DocumentDocumentAndEntityInformationLineItems" xlink:type="locator" xlink:label="arwr_DocumentDocumentAndEntityInformationLineItems" />
    <loc xlink:href="http://xbrl.sec.gov/dei/2013/dei-2013-01-31.xsd#dei_EntityDomain" xlink:type="locator" xlink:label="dei_EntityDomain" />
    <loc xlink:href="http://xbrl.sec.gov/dei/2013/dei-2013-01-31.xsd#dei_LegalEntityAxis" xlink:type="locator" xlink:label="dei_LegalEntityAxis" />
    <loc xlink:href="arwr-20140331.xsd#arwr_DocumentDocumentAndEntityInformationTable" xlink:type="locator" xlink:label="arwr_DocumentDocumentAndEntityInformationTable" />
    <loc xlink:href="arwr-20140331.xsd#arwr_DocumentDocumentAndEntityInformationAbstract" xlink:type="locator" xlink:label="arwr_DocumentDocumentAndEntityInformationAbstract" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="arwr_DocumentDocumentAndEntityInformationAbstract" xlink:to="arwr_DocumentDocumentAndEntityInformationTable" order="10010.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="arwr_DocumentDocumentAndEntityInformationTable" xlink:to="dei_LegalEntityAxis" order="10020.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="dei_LegalEntityAxis" xlink:to="dei_EntityDomain" order="10030.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="arwr_DocumentDocumentAndEntityInformationTable" xlink:to="arwr_DocumentDocumentAndEntityInformationLineItems" order="10040.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="arwr_DocumentDocumentAndEntityInformationLineItems" xlink:to="dei_DocumentType" order="10080.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="arwr_DocumentDocumentAndEntityInformationLineItems" xlink:to="dei_AmendmentFlag" order="10140.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="arwr_DocumentDocumentAndEntityInformationLineItems" xlink:to="dei_DocumentPeriodEndDate" order="10200.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="arwr_DocumentDocumentAndEntityInformationLineItems" xlink:to="dei_DocumentFiscalYearFocus" order="10260.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="arwr_DocumentDocumentAndEntityInformationLineItems" xlink:to="dei_DocumentFiscalPeriodFocus" order="10320.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="arwr_DocumentDocumentAndEntityInformationLineItems" xlink:to="dei_TradingSymbol" order="10380.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="arwr_DocumentDocumentAndEntityInformationLineItems" xlink:to="dei_EntityRegistrantName" order="10440.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="arwr_DocumentDocumentAndEntityInformationLineItems" xlink:to="dei_EntityCentralIndexKey" order="10500.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="arwr_DocumentDocumentAndEntityInformationLineItems" xlink:to="dei_CurrentFiscalYearEndDate" order="10560.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="arwr_DocumentDocumentAndEntityInformationLineItems" xlink:to="dei_EntityFilerCategory" order="10620.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="arwr_DocumentDocumentAndEntityInformationLineItems" xlink:to="dei_EntityCommonStockSharesOutstanding" order="10680.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
  </presentationLink>
  <roleRef roleURI="http://www.arrowheadresearch.com/20140331/taxonomy/role/StatementConsolidatedBalanceSheets" xlink:href="arwr-20140331.xsd#Role_StatementConsolidatedBalanceSheets" xlink:type="simple" />
  <presentationLink xlink:type="extended" xlink:role="http://www.arrowheadresearch.com/20140331/taxonomy/role/StatementConsolidatedBalanceSheets">
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_LiabilitiesAndStockholdersEquity" xlink:type="locator" xlink:label="us-gaap_LiabilitiesAndStockholdersEquity" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest" xlink:type="locator" xlink:label="us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_MinorityInterest" xlink:type="locator" xlink:label="us-gaap_MinorityInterest" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_StockholdersEquity" xlink:type="locator" xlink:label="us-gaap_StockholdersEquity" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_RetainedEarningsAccumulatedDeficit" xlink:type="locator" xlink:label="us-gaap_RetainedEarningsAccumulatedDeficit" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_AdditionalPaidInCapitalCommonStock" xlink:type="locator" xlink:label="us-gaap_AdditionalPaidInCapitalCommonStock" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_CommonStockValue" xlink:type="locator" xlink:label="us-gaap_CommonStockValue" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_PreferredStockValue" xlink:type="locator" xlink:label="us-gaap_PreferredStockValue" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterestAbstract" xlink:type="locator" xlink:label="us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterestAbstract" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_CommitmentsAndContingencies" xlink:type="locator" xlink:label="us-gaap_CommitmentsAndContingencies" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_LiabilitiesNoncurrent" xlink:type="locator" xlink:label="us-gaap_LiabilitiesNoncurrent" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_OtherLiabilitiesNoncurrent" xlink:type="locator" xlink:label="us-gaap_OtherLiabilitiesNoncurrent" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_CapitalLeaseObligationsNoncurrent" xlink:type="locator" xlink:label="us-gaap_CapitalLeaseObligationsNoncurrent" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_LongTermNotesPayable" xlink:type="locator" xlink:label="us-gaap_LongTermNotesPayable" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_LiabilitiesNoncurrentAbstract" xlink:type="locator" xlink:label="us-gaap_LiabilitiesNoncurrentAbstract" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_LiabilitiesCurrent" xlink:type="locator" xlink:label="us-gaap_LiabilitiesCurrent" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_OtherLiabilitiesCurrent" xlink:type="locator" xlink:label="us-gaap_OtherLiabilitiesCurrent" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_NotesPayableCurrent" xlink:type="locator" xlink:label="us-gaap_NotesPayableCurrent" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_CapitalLeaseObligationsCurrent" xlink:type="locator" xlink:label="us-gaap_CapitalLeaseObligationsCurrent" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DerivativeLiabilitiesCurrent" xlink:type="locator" xlink:label="us-gaap_DerivativeLiabilitiesCurrent" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DeferredRevenueCurrent" xlink:type="locator" xlink:label="us-gaap_DeferredRevenueCurrent" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_EmployeeRelatedLiabilitiesCurrent" xlink:type="locator" xlink:label="us-gaap_EmployeeRelatedLiabilitiesCurrent" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_AccruedLiabilitiesCurrent" xlink:type="locator" xlink:label="us-gaap_AccruedLiabilitiesCurrent" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_AccountsPayableCurrent" xlink:type="locator" xlink:label="us-gaap_AccountsPayableCurrent" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_LiabilitiesCurrentAbstract" xlink:type="locator" xlink:label="us-gaap_LiabilitiesCurrentAbstract" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_Assets" xlink:type="locator" xlink:label="us-gaap_Assets" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_OtherAssetsMiscellaneousNoncurrent" xlink:type="locator" xlink:label="us-gaap_OtherAssetsMiscellaneousNoncurrent" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_InvestmentOwnedAtCost" xlink:type="locator" xlink:label="us-gaap_InvestmentOwnedAtCost" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsGross" xlink:type="locator" xlink:label="us-gaap_FiniteLivedIntangibleAssetsGross" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_PropertyPlantAndEquipmentNet" xlink:type="locator" xlink:label="us-gaap_PropertyPlantAndEquipmentNet" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_AssetsCurrent" xlink:type="locator" xlink:label="us-gaap_AssetsCurrent" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_MarketableSecuritiesCurrent" xlink:type="locator" xlink:label="us-gaap_MarketableSecuritiesCurrent" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_OtherAssetsCurrent" xlink:type="locator" xlink:label="us-gaap_OtherAssetsCurrent" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_PrepaidExpenseCurrent" xlink:type="locator" xlink:label="us-gaap_PrepaidExpenseCurrent" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_AccountsReceivableNetCurrent" xlink:type="locator" xlink:label="us-gaap_AccountsReceivableNetCurrent" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_CashAndCashEquivalentsAtCarryingValue" xlink:type="locator" xlink:label="us-gaap_CashAndCashEquivalentsAtCarryingValue" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_AssetsCurrentAbstract" xlink:type="locator" xlink:label="us-gaap_AssetsCurrentAbstract" />
    <loc xlink:href="arwr-20140331.xsd#arwr_StatementConsolidatedBalanceSheetsLineItems" xlink:type="locator" xlink:label="arwr_StatementConsolidatedBalanceSheetsLineItems" />
    <loc xlink:href="http://xbrl.sec.gov/dei/2013/dei-2013-01-31.xsd#dei_EntityDomain" xlink:type="locator" xlink:label="dei_EntityDomain" />
    <loc xlink:href="http://xbrl.sec.gov/dei/2013/dei-2013-01-31.xsd#dei_LegalEntityAxis" xlink:type="locator" xlink:label="dei_LegalEntityAxis" />
    <loc xlink:href="arwr-20140331.xsd#arwr_StatementConsolidatedBalanceSheetsTable" xlink:type="locator" xlink:label="arwr_StatementConsolidatedBalanceSheetsTable" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_StatementOfFinancialPositionAbstract" xlink:type="locator" xlink:label="us-gaap_StatementOfFinancialPositionAbstract" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementOfFinancialPositionAbstract" xlink:to="arwr_StatementConsolidatedBalanceSheetsTable" order="10310.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="arwr_StatementConsolidatedBalanceSheetsTable" xlink:to="dei_LegalEntityAxis" order="10320.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="dei_LegalEntityAxis" xlink:to="dei_EntityDomain" order="10330.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="arwr_StatementConsolidatedBalanceSheetsTable" xlink:to="arwr_StatementConsolidatedBalanceSheetsLineItems" order="10340.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="arwr_StatementConsolidatedBalanceSheetsLineItems" xlink:to="us-gaap_AssetsCurrentAbstract" order="10380.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AssetsCurrentAbstract" xlink:to="us-gaap_CashAndCashEquivalentsAtCarryingValue" order="10460.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AssetsCurrentAbstract" xlink:to="us-gaap_AccountsReceivableNetCurrent" order="10540.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AssetsCurrentAbstract" xlink:to="us-gaap_PrepaidExpenseCurrent" order="10600.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AssetsCurrentAbstract" xlink:to="us-gaap_OtherAssetsCurrent" order="10680.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AssetsCurrentAbstract" xlink:to="us-gaap_MarketableSecuritiesCurrent" order="10760.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AssetsCurrentAbstract" xlink:to="us-gaap_AssetsCurrent" order="10840.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/totalLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AssetsCurrentAbstract" xlink:to="us-gaap_PropertyPlantAndEquipmentNet" order="10920.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AssetsCurrentAbstract" xlink:to="us-gaap_FiniteLivedIntangibleAssetsGross" order="11000.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AssetsCurrentAbstract" xlink:to="us-gaap_InvestmentOwnedAtCost" order="11080.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AssetsCurrentAbstract" xlink:to="us-gaap_OtherAssetsMiscellaneousNoncurrent" order="11160.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AssetsCurrentAbstract" xlink:to="us-gaap_Assets" order="11240.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/totalLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="arwr_StatementConsolidatedBalanceSheetsLineItems" xlink:to="us-gaap_LiabilitiesCurrentAbstract" order="11320.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_LiabilitiesCurrentAbstract" xlink:to="us-gaap_AccountsPayableCurrent" order="11400.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_LiabilitiesCurrentAbstract" xlink:to="us-gaap_AccruedLiabilitiesCurrent" order="11480.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_LiabilitiesCurrentAbstract" xlink:to="us-gaap_EmployeeRelatedLiabilitiesCurrent" order="11560.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_LiabilitiesCurrentAbstract" xlink:to="us-gaap_DeferredRevenueCurrent" order="11640.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_LiabilitiesCurrentAbstract" xlink:to="us-gaap_DerivativeLiabilitiesCurrent" order="11720.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_LiabilitiesCurrentAbstract" xlink:to="us-gaap_CapitalLeaseObligationsCurrent" order="11800.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_LiabilitiesCurrentAbstract" xlink:to="us-gaap_NotesPayableCurrent" order="11880.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_LiabilitiesCurrentAbstract" xlink:to="us-gaap_OtherLiabilitiesCurrent" order="11960.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_LiabilitiesCurrentAbstract" xlink:to="us-gaap_LiabilitiesCurrent" order="12040.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/totalLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="arwr_StatementConsolidatedBalanceSheetsLineItems" xlink:to="us-gaap_LiabilitiesNoncurrentAbstract" order="12120.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_LiabilitiesNoncurrentAbstract" xlink:to="us-gaap_LongTermNotesPayable" order="12200.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_LiabilitiesNoncurrentAbstract" xlink:to="us-gaap_CapitalLeaseObligationsNoncurrent" order="12260.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_LiabilitiesNoncurrentAbstract" xlink:to="us-gaap_OtherLiabilitiesNoncurrent" order="12340.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_LiabilitiesNoncurrentAbstract" xlink:to="us-gaap_LiabilitiesNoncurrent" order="12420.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/totalLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="arwr_StatementConsolidatedBalanceSheetsLineItems" xlink:to="us-gaap_CommitmentsAndContingencies" order="12500.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="arwr_StatementConsolidatedBalanceSheetsLineItems" xlink:to="us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterestAbstract" order="12580.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterestAbstract" xlink:to="us-gaap_PreferredStockValue" order="12660.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="arwr_StatementConsolidatedBalanceSheetsLineItems" xlink:to="us-gaap_CommonStockValue" order="12740.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="arwr_StatementConsolidatedBalanceSheetsLineItems" xlink:to="us-gaap_AdditionalPaidInCapitalCommonStock" order="12820.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="arwr_StatementConsolidatedBalanceSheetsLineItems" xlink:to="us-gaap_RetainedEarningsAccumulatedDeficit" order="12900.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="arwr_StatementConsolidatedBalanceSheetsLineItems" xlink:to="us-gaap_StockholdersEquity" order="12980.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/totalLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="arwr_StatementConsolidatedBalanceSheetsLineItems" xlink:to="us-gaap_MinorityInterest" order="13060.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="arwr_StatementConsolidatedBalanceSheetsLineItems" xlink:to="us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest" order="13140.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/totalLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="arwr_StatementConsolidatedBalanceSheetsLineItems" xlink:to="us-gaap_LiabilitiesAndStockholdersEquity" order="13220.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/totalLabel" />
  </presentationLink>
  <roleRef roleURI="http://www.arrowheadresearch.com/20140331/taxonomy/role/StatementConsolidatedBalanceSheetsParenthetical" xlink:href="arwr-20140331.xsd#Role_StatementConsolidatedBalanceSheetsParenthetical" xlink:type="simple" />
  <presentationLink xlink:type="extended" xlink:role="http://www.arrowheadresearch.com/20140331/taxonomy/role/StatementConsolidatedBalanceSheetsParenthetical">
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_CommonStockSharesOutstanding" xlink:type="locator" xlink:label="us-gaap_CommonStockSharesOutstanding" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_CommonStockSharesIssued" xlink:type="locator" xlink:label="us-gaap_CommonStockSharesIssued" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_CommonStockSharesAuthorized" xlink:type="locator" xlink:label="us-gaap_CommonStockSharesAuthorized" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_CommonStockParOrStatedValuePerShare" xlink:type="locator" xlink:label="us-gaap_CommonStockParOrStatedValuePerShare" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_PreferredStockSharesOutstanding" xlink:type="locator" xlink:label="us-gaap_PreferredStockSharesOutstanding" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_PreferredStockSharesIssued" xlink:type="locator" xlink:label="us-gaap_PreferredStockSharesIssued" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_PreferredStockSharesAuthorized" xlink:type="locator" xlink:label="us-gaap_PreferredStockSharesAuthorized" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_PreferredStockParOrStatedValuePerShare" xlink:type="locator" xlink:label="us-gaap_PreferredStockParOrStatedValuePerShare" />
    <loc xlink:href="arwr-20140331.xsd#arwr_StatementConsolidatedBalanceSheetsParentheticalLineItems" xlink:type="locator" xlink:label="arwr_StatementConsolidatedBalanceSheetsParentheticalLineItems" />
    <loc xlink:href="http://xbrl.sec.gov/dei/2013/dei-2013-01-31.xsd#dei_EntityDomain" xlink:type="locator" xlink:label="dei_EntityDomain" />
    <loc xlink:href="http://xbrl.sec.gov/dei/2013/dei-2013-01-31.xsd#dei_LegalEntityAxis" xlink:type="locator" xlink:label="dei_LegalEntityAxis" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_StatementTable" xlink:type="locator" xlink:label="us-gaap_StatementTable" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_StatementOfFinancialPositionAbstract" xlink:type="locator" xlink:label="us-gaap_StatementOfFinancialPositionAbstract" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementOfFinancialPositionAbstract" xlink:to="us-gaap_StatementTable" order="10010.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementTable" xlink:to="dei_LegalEntityAxis" order="10020.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="dei_LegalEntityAxis" xlink:to="dei_EntityDomain" order="10030.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementTable" xlink:to="arwr_StatementConsolidatedBalanceSheetsParentheticalLineItems" order="10040.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="arwr_StatementConsolidatedBalanceSheetsParentheticalLineItems" xlink:to="us-gaap_PreferredStockParOrStatedValuePerShare" order="10080.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="arwr_StatementConsolidatedBalanceSheetsParentheticalLineItems" xlink:to="us-gaap_PreferredStockSharesAuthorized" order="10160.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="arwr_StatementConsolidatedBalanceSheetsParentheticalLineItems" xlink:to="us-gaap_PreferredStockSharesIssued" order="10240.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="arwr_StatementConsolidatedBalanceSheetsParentheticalLineItems" xlink:to="us-gaap_PreferredStockSharesOutstanding" order="10320.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="arwr_StatementConsolidatedBalanceSheetsParentheticalLineItems" xlink:to="us-gaap_CommonStockParOrStatedValuePerShare" order="10400.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="arwr_StatementConsolidatedBalanceSheetsParentheticalLineItems" xlink:to="us-gaap_CommonStockSharesAuthorized" order="10480.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="arwr_StatementConsolidatedBalanceSheetsParentheticalLineItems" xlink:to="us-gaap_CommonStockSharesIssued" order="10560.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="arwr_StatementConsolidatedBalanceSheetsParentheticalLineItems" xlink:to="us-gaap_CommonStockSharesOutstanding" order="10640.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
  </presentationLink>
  <roleRef roleURI="http://www.arrowheadresearch.com/20140331/taxonomy/role/StatementConsolidatedStatementsOfOperations" xlink:href="arwr-20140331.xsd#Role_StatementConsolidatedStatementsOfOperations" xlink:type="simple" />
  <presentationLink xlink:type="extended" xlink:role="http://www.arrowheadresearch.com/20140331/taxonomy/role/StatementConsolidatedStatementsOfOperations">
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_WeightedAverageNumberOfShareOutstandingBasicAndDiluted" xlink:type="locator" xlink:label="us-gaap_WeightedAverageNumberOfShareOutstandingBasicAndDiluted" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_EarningsPerShareBasicAndDiluted" xlink:type="locator" xlink:label="us-gaap_EarningsPerShareBasicAndDiluted" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_NetIncomeLoss" xlink:type="locator" xlink:label="us-gaap_NetIncomeLoss" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_NetIncomeLossAttributableToNoncontrollingInterest" xlink:type="locator" xlink:label="us-gaap_NetIncomeLossAttributableToNoncontrollingInterest" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ProfitLoss" xlink:type="locator" xlink:label="us-gaap_ProfitLoss" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_IncomeLossFromDiscontinuedOperationsNetOfTax" xlink:type="locator" xlink:label="us-gaap_IncomeLossFromDiscontinuedOperationsNetOfTax" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DiscontinuedOperationGainLossOnDisposalOfDiscontinuedOperationNetOfTax" xlink:type="locator" xlink:label="us-gaap_DiscontinuedOperationGainLossOnDisposalOfDiscontinuedOperationNetOfTax" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DiscontinuedOperationIncomeLossFromDiscontinuedOperationDuringPhaseOutPeriodNetOfTax" xlink:type="locator" xlink:label="us-gaap_DiscontinuedOperationIncomeLossFromDiscontinuedOperationDuringPhaseOutPeriodNetOfTax" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_IncomeLossFromContinuingOperationsIncludingPortionAttributableToNoncontrollingInterest" xlink:type="locator" xlink:label="us-gaap_IncomeLossFromContinuingOperationsIncludingPortionAttributableToNoncontrollingInterest" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_IncomeTaxExpenseBenefit" xlink:type="locator" xlink:label="us-gaap_IncomeTaxExpenseBenefit" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest" xlink:type="locator" xlink:label="us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_NonoperatingIncomeExpense" xlink:type="locator" xlink:label="us-gaap_NonoperatingIncomeExpense" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_OtherNonoperatingIncomeExpense" xlink:type="locator" xlink:label="us-gaap_OtherNonoperatingIncomeExpense" />
    <loc xlink:href="arwr-20140331.xsd#arwr_GainLossOnSaleOfStockInSubsidiary" xlink:type="locator" xlink:label="arwr_GainLossOnSaleOfStockInSubsidiary" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_UnrealizedGainLossOnDerivatives" xlink:type="locator" xlink:label="us-gaap_UnrealizedGainLossOnDerivatives" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_InterestIncomeExpenseNet" xlink:type="locator" xlink:label="us-gaap_InterestIncomeExpenseNet" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_MarketableSecuritiesGainLoss" xlink:type="locator" xlink:label="us-gaap_MarketableSecuritiesGainLoss" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_GainLossOnSaleOfPropertyPlantEquipment" xlink:type="locator" xlink:label="us-gaap_GainLossOnSaleOfPropertyPlantEquipment" />
    <loc xlink:href="arwr-20140331.xsd#arwr_GainOnAcquisition" xlink:type="locator" xlink:label="arwr_GainOnAcquisition" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ImpairmentOfInvestments" xlink:type="locator" xlink:label="us-gaap_ImpairmentOfInvestments" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_IncomeLossFromEquityMethodInvestments" xlink:type="locator" xlink:label="us-gaap_IncomeLossFromEquityMethodInvestments" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_NonoperatingIncomeExpenseAbstract" xlink:type="locator" xlink:label="us-gaap_NonoperatingIncomeExpenseAbstract" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_OperatingIncomeLoss" xlink:type="locator" xlink:label="us-gaap_OperatingIncomeLoss" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_OperatingExpenses" xlink:type="locator" xlink:label="us-gaap_OperatingExpenses" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_BusinessCombinationContingentConsiderationArrangementsChangeInAmountOfContingentConsiderationLiability1" xlink:type="locator" xlink:label="us-gaap_BusinessCombinationContingentConsiderationArrangementsChangeInAmountOfContingentConsiderationLiability1" />
    <loc xlink:href="arwr-20140331.xsd#arwr_ImpairmentOfIntangibleAssets" xlink:type="locator" xlink:label="arwr_ImpairmentOfIntangibleAssets" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DepreciationDepletionAndAmortization" xlink:type="locator" xlink:label="us-gaap_DepreciationDepletionAndAmortization" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ShareBasedCompensation" xlink:type="locator" xlink:label="us-gaap_ShareBasedCompensation" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ResearchAndDevelopmentExpense" xlink:type="locator" xlink:label="us-gaap_ResearchAndDevelopmentExpense" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_GeneralAndAdministrativeExpense" xlink:type="locator" xlink:label="us-gaap_GeneralAndAdministrativeExpense" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_LaborAndRelatedExpense" xlink:type="locator" xlink:label="us-gaap_LaborAndRelatedExpense" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_OperatingExpensesAbstract" xlink:type="locator" xlink:label="us-gaap_OperatingExpensesAbstract" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_Revenues" xlink:type="locator" xlink:label="us-gaap_Revenues" />
    <loc xlink:href="arwr-20140331.xsd#arwr_StatementConsolidatedStatementsOfOperationsLineItems" xlink:type="locator" xlink:label="arwr_StatementConsolidatedStatementsOfOperationsLineItems" />
    <loc xlink:href="http://xbrl.sec.gov/dei/2013/dei-2013-01-31.xsd#dei_EntityDomain" xlink:type="locator" xlink:label="dei_EntityDomain" />
    <loc xlink:href="http://xbrl.sec.gov/dei/2013/dei-2013-01-31.xsd#dei_LegalEntityAxis" xlink:type="locator" xlink:label="dei_LegalEntityAxis" />
    <loc xlink:href="arwr-20140331.xsd#arwr_StatementConsolidatedStatementsOfOperationsTable" xlink:type="locator" xlink:label="arwr_StatementConsolidatedStatementsOfOperationsTable" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_IncomeStatementAbstract" xlink:type="locator" xlink:label="us-gaap_IncomeStatementAbstract" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_IncomeStatementAbstract" xlink:to="arwr_StatementConsolidatedStatementsOfOperationsTable" order="10280.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="arwr_StatementConsolidatedStatementsOfOperationsTable" xlink:to="dei_LegalEntityAxis" order="10290.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="dei_LegalEntityAxis" xlink:to="dei_EntityDomain" order="10300.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="arwr_StatementConsolidatedStatementsOfOperationsTable" xlink:to="arwr_StatementConsolidatedStatementsOfOperationsLineItems" order="10310.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="arwr_StatementConsolidatedStatementsOfOperationsLineItems" xlink:to="us-gaap_Revenues" order="10350.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="arwr_StatementConsolidatedStatementsOfOperationsLineItems" xlink:to="us-gaap_OperatingExpensesAbstract" order="10550.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_OperatingExpensesAbstract" xlink:to="us-gaap_LaborAndRelatedExpense" order="10750.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_OperatingExpensesAbstract" xlink:to="us-gaap_GeneralAndAdministrativeExpense" order="10950.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_OperatingExpensesAbstract" xlink:to="us-gaap_ResearchAndDevelopmentExpense" order="11150.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_OperatingExpensesAbstract" xlink:to="us-gaap_ShareBasedCompensation" order="11350.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_OperatingExpensesAbstract" xlink:to="us-gaap_DepreciationDepletionAndAmortization" order="11550.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_OperatingExpensesAbstract" xlink:to="arwr_ImpairmentOfIntangibleAssets" order="11750.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_OperatingExpensesAbstract" xlink:to="us-gaap_BusinessCombinationContingentConsiderationArrangementsChangeInAmountOfContingentConsiderationLiability1" order="11870.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_OperatingExpensesAbstract" xlink:to="us-gaap_OperatingExpenses" order="11990.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/totalLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="arwr_StatementConsolidatedStatementsOfOperationsLineItems" xlink:to="us-gaap_OperatingIncomeLoss" order="12190.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/totalLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="arwr_StatementConsolidatedStatementsOfOperationsLineItems" xlink:to="us-gaap_NonoperatingIncomeExpenseAbstract" order="12390.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_NonoperatingIncomeExpenseAbstract" xlink:to="us-gaap_IncomeLossFromEquityMethodInvestments" order="12590.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_NonoperatingIncomeExpenseAbstract" xlink:to="us-gaap_ImpairmentOfInvestments" order="12790.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2009/role/negatedLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_NonoperatingIncomeExpenseAbstract" xlink:to="arwr_GainOnAcquisition" order="12910.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_NonoperatingIncomeExpenseAbstract" xlink:to="us-gaap_GainLossOnSaleOfPropertyPlantEquipment" order="13030.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_NonoperatingIncomeExpenseAbstract" xlink:to="us-gaap_MarketableSecuritiesGainLoss" order="13230.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_NonoperatingIncomeExpenseAbstract" xlink:to="us-gaap_InterestIncomeExpenseNet" order="13350.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_NonoperatingIncomeExpenseAbstract" xlink:to="us-gaap_UnrealizedGainLossOnDerivatives" order="13550.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_NonoperatingIncomeExpenseAbstract" xlink:to="arwr_GainLossOnSaleOfStockInSubsidiary" order="13750.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_NonoperatingIncomeExpenseAbstract" xlink:to="us-gaap_OtherNonoperatingIncomeExpense" order="13870.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_NonoperatingIncomeExpenseAbstract" xlink:to="us-gaap_NonoperatingIncomeExpense" order="14070.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/totalLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_NonoperatingIncomeExpenseAbstract" xlink:to="us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest" order="14270.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/totalLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_NonoperatingIncomeExpenseAbstract" xlink:to="us-gaap_IncomeTaxExpenseBenefit" order="14470.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2009/role/negatedLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_NonoperatingIncomeExpenseAbstract" xlink:to="us-gaap_IncomeLossFromContinuingOperationsIncludingPortionAttributableToNoncontrollingInterest" order="14670.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/totalLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_NonoperatingIncomeExpenseAbstract" xlink:to="us-gaap_DiscontinuedOperationIncomeLossFromDiscontinuedOperationDuringPhaseOutPeriodNetOfTax" order="14870.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_NonoperatingIncomeExpenseAbstract" xlink:to="us-gaap_DiscontinuedOperationGainLossOnDisposalOfDiscontinuedOperationNetOfTax" order="15030.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_NonoperatingIncomeExpenseAbstract" xlink:to="us-gaap_IncomeLossFromDiscontinuedOperationsNetOfTax" order="15150.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/totalLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_NonoperatingIncomeExpenseAbstract" xlink:to="us-gaap_ProfitLoss" order="15310.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/totalLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_NonoperatingIncomeExpenseAbstract" xlink:to="us-gaap_NetIncomeLossAttributableToNoncontrollingInterest" order="15510.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2009/role/negatedLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_NonoperatingIncomeExpenseAbstract" xlink:to="us-gaap_NetIncomeLoss" order="15710.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/totalLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="arwr_StatementConsolidatedStatementsOfOperationsLineItems" xlink:to="us-gaap_EarningsPerShareBasicAndDiluted" order="15910.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="arwr_StatementConsolidatedStatementsOfOperationsLineItems" xlink:to="us-gaap_WeightedAverageNumberOfShareOutstandingBasicAndDiluted" order="16090.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
  </presentationLink>
  <roleRef roleURI="http://www.arrowheadresearch.com/20140331/taxonomy/role/StatementConsolidatedStatementOfStockholdersEquity" xlink:href="arwr-20140331.xsd#Role_StatementConsolidatedStatementOfStockholdersEquity" xlink:type="simple" />
  <presentationLink xlink:type="extended" xlink:role="http://www.arrowheadresearch.com/20140331/taxonomy/role/StatementConsolidatedStatementOfStockholdersEquity">
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_OtherComprehensiveIncomeUnrealizedGainLossOnDerivativesArisingDuringPeriodNetOfTax" xlink:type="locator" xlink:label="us-gaap_OtherComprehensiveIncomeUnrealizedGainLossOnDerivativesArisingDuringPeriodNetOfTax" />
    <loc xlink:href="arwr-20140331.xsd#arwr_CancellationOfSubscriptionReceivables" xlink:type="locator" xlink:label="arwr_CancellationOfSubscriptionReceivables" />
    <loc xlink:href="arwr-20140331.xsd#arwr_CancellationOfSharesRelatedToSubscriptionReceivables" xlink:type="locator" xlink:label="arwr_CancellationOfSharesRelatedToSubscriptionReceivables" />
    <loc xlink:href="arwr-20140331.xsd#arwr_SubscriptionReceivable" xlink:type="locator" xlink:label="arwr_SubscriptionReceivable" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_StockIssuedDuringPeriodValueConversionOfUnits" xlink:type="locator" xlink:label="us-gaap_StockIssuedDuringPeriodValueConversionOfUnits" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_StockIssuedDuringPeriodSharesConversionOfUnits" xlink:type="locator" xlink:label="us-gaap_StockIssuedDuringPeriodSharesConversionOfUnits" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_StockIssuedDuringPeriodSharesReverseStockSplits" xlink:type="locator" xlink:label="us-gaap_StockIssuedDuringPeriodSharesReverseStockSplits" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_OtherComprehensiveIncomeLossDerivativesQualifyingAsHedgesNetOfTax" xlink:type="locator" xlink:label="us-gaap_OtherComprehensiveIncomeLossDerivativesQualifyingAsHedgesNetOfTax" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_NoncontrollingInterestIncreaseFromSaleOfParentEquityInterest" xlink:type="locator" xlink:label="us-gaap_NoncontrollingInterestIncreaseFromSaleOfParentEquityInterest" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_AdjustmentsToAdditionalPaidInCapitalConvertibleDebtWithConversionFeature" xlink:type="locator" xlink:label="us-gaap_AdjustmentsToAdditionalPaidInCapitalConvertibleDebtWithConversionFeature" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ProceedsFromIssuanceOfPreferredStockAndPreferenceStock" xlink:type="locator" xlink:label="us-gaap_ProceedsFromIssuanceOfPreferredStockAndPreferenceStock" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_AdjustmentsToAdditionalPaidInCapitalEquityComponentOfConvertibleDebt" xlink:type="locator" xlink:label="us-gaap_AdjustmentsToAdditionalPaidInCapitalEquityComponentOfConvertibleDebt" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_NoncontrollingInterestIncreaseFromSubsidiaryEquityIssuance" xlink:type="locator" xlink:label="us-gaap_NoncontrollingInterestIncreaseFromSubsidiaryEquityIssuance" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue" xlink:type="locator" xlink:label="us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_StockIssuedDuringPeriodValueStockOptionsExercised" xlink:type="locator" xlink:label="us-gaap_StockIssuedDuringPeriodValueStockOptionsExercised" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised" xlink:type="locator" xlink:label="us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_SharesIssued" xlink:type="locator" xlink:label="us-gaap_SharesIssued" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest" xlink:type="locator" xlink:label="us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest_li0l2" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ProfitLoss" xlink:type="locator" xlink:label="us-gaap_ProfitLoss" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_AdjustmentsToAdditionalPaidInCapitalStockIssuedIssuanceCosts" xlink:type="locator" xlink:label="us-gaap_AdjustmentsToAdditionalPaidInCapitalStockIssuedIssuanceCosts" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_StockIssuedDuringPeriodValueNewIssues" xlink:type="locator" xlink:label="us-gaap_StockIssuedDuringPeriodValueNewIssues" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_StockIssuedDuringPeriodSharesNewIssues" xlink:type="locator" xlink:label="us-gaap_StockIssuedDuringPeriodSharesNewIssues" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest" xlink:type="locator" xlink:label="us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_StatementLineItems" xlink:type="locator" xlink:label="us-gaap_StatementLineItems" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_NoncontrollingInterestMember" xlink:type="locator" xlink:label="us-gaap_NoncontrollingInterestMember" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_AccumulatedDeficitDuringDevelopmentStageMember" xlink:type="locator" xlink:label="us-gaap_AccumulatedDeficitDuringDevelopmentStageMember" />
    <loc xlink:href="arwr-20140331.xsd#arwr_SubscriptionsReceivableMember" xlink:type="locator" xlink:label="arwr_SubscriptionsReceivableMember" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_AdditionalPaidInCapitalMember" xlink:type="locator" xlink:label="us-gaap_AdditionalPaidInCapitalMember" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_PreferredStockMember" xlink:type="locator" xlink:label="us-gaap_PreferredStockMember" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_CommonStockMember" xlink:type="locator" xlink:label="us-gaap_CommonStockMember" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_EquityComponentDomain" xlink:type="locator" xlink:label="us-gaap_EquityComponentDomain" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_StatementEquityComponentsAxis" xlink:type="locator" xlink:label="us-gaap_StatementEquityComponentsAxis" />
    <loc xlink:href="arwr-20140331.xsd#arwr_IssuedToGallowayMember" xlink:type="locator" xlink:label="arwr_IssuedToGallowayMember" />
    <loc xlink:href="arwr-20140331.xsd#arwr_IssuedAtEighteenDollarAndNinetyFiveCentsPerShareMember" xlink:type="locator" xlink:label="arwr_IssuedAtEighteenDollarAndNinetyFiveCentsPerShareMember" />
    <loc xlink:href="arwr-20140331.xsd#arwr_IssuedAtFiveDollarsAndEightySixCentsPerShareMember" xlink:type="locator" xlink:label="arwr_IssuedAtFiveDollarsAndEightySixCentsPerShareMember" />
    <loc xlink:href="arwr-20140331.xsd#arwr_IssuedAtOneDollarAndEightyThreeCentsPerShareMember" xlink:type="locator" xlink:label="arwr_IssuedAtOneDollarAndEightyThreeCentsPerShareMember" />
    <loc xlink:href="arwr-20140331.xsd#arwr_IssuedAtTwoDollarsAndTwelveCentsPerShareMember" xlink:type="locator" xlink:label="arwr_IssuedAtTwoDollarsAndTwelveCentsPerShareMember" />
    <loc xlink:href="arwr-20140331.xsd#arwr_IssuedAtTwoDollarsAndTwentySixCentsPerShareMember" xlink:type="locator" xlink:label="arwr_IssuedAtTwoDollarsAndTwentySixCentsPerShareMember" />
    <loc xlink:href="arwr-20140331.xsd#arwr_IssuedAtFourDollarsAndFortyNineCentsPerShareMember" xlink:type="locator" xlink:label="arwr_IssuedAtFourDollarsAndFortyNineCentsPerShareMember" />
    <loc xlink:href="arwr-20140331.xsd#arwr_PreferredStockIssuedAtThousandDollarsPerShareMember" xlink:type="locator" xlink:label="arwr_PreferredStockIssuedAtThousandDollarsPerShareMember" />
    <loc xlink:href="arwr-20140331.xsd#arwr_IssuedUnderCommittedCapitalAgreementMember" xlink:type="locator" xlink:label="arwr_IssuedUnderCommittedCapitalAgreementMember" />
    <loc xlink:href="arwr-20140331.xsd#arwr_IssuedAtTwoDollarsAndSeventySixCentsPerShareMember" xlink:type="locator" xlink:label="arwr_IssuedAtTwoDollarsAndSeventySixCentsPerShareMember" />
    <loc xlink:href="arwr-20140331.xsd#arwr_IssuedAtFiveDollarsAndElevenCentsPerShareMember" xlink:type="locator" xlink:label="arwr_IssuedAtFiveDollarsAndElevenCentsPerShareMember" />
    <loc xlink:href="arwr-20140331.xsd#arwr_IssuedAtSixDollarsAndTwentyThreeCentsPerShareMember" xlink:type="locator" xlink:label="arwr_IssuedAtSixDollarsAndTwentyThreeCentsPerShareMember" />
    <loc xlink:href="arwr-20140331.xsd#arwr_IssuedAtFourDollarsPerShareMember" xlink:type="locator" xlink:label="arwr_IssuedAtFourDollarsPerShareMember" />
    <loc xlink:href="arwr-20140331.xsd#arwr_IssuedAtThreeDollarsAndSeventyCentsPerShareMember" xlink:type="locator" xlink:label="arwr_IssuedAtThreeDollarsAndSeventyCentsPerShareMember" />
    <loc xlink:href="arwr-20140331.xsd#arwr_IssuanceOfCommonStockForSubscriptionMember" xlink:type="locator" xlink:label="arwr_IssuanceOfCommonStockForSubscriptionMember" />
    <loc xlink:href="arwr-20140331.xsd#arwr_IssuedAtThreeDollarsAndEightyCentsPerShareMember" xlink:type="locator" xlink:label="arwr_IssuedAtThreeDollarsAndEightyCentsPerShareMember" />
    <loc xlink:href="arwr-20140331.xsd#arwr_IssuedToCalandoStockholdersInExchangeForCalandoSSharesMember" xlink:type="locator" xlink:label="arwr_IssuedToCalandoStockholdersInExchangeForCalandoSSharesMember" />
    <loc xlink:href="arwr-20140331.xsd#arwr_IssuedAtThirteenDollarsAndTwelveCentsPerShareMember" xlink:type="locator" xlink:label="arwr_IssuedAtThirteenDollarsAndTwelveCentsPerShareMember" />
    <loc xlink:href="arwr-20140331.xsd#arwr_IssuedAtSixDollarsAndThirtyFourCentsPerShareMember" xlink:type="locator" xlink:label="arwr_IssuedAtSixDollarsAndThirtyFourCentsPerShareMember" />
    <loc xlink:href="arwr-20140331.xsd#arwr_IssuedToUnidymStockholdersInExchangeForUnidymsSharesMember" xlink:type="locator" xlink:label="arwr_IssuedToUnidymStockholdersInExchangeForUnidymsSharesMember" />
    <loc xlink:href="arwr-20140331.xsd#arwr_IssuedAtThreeDollarsPerShareMember" xlink:type="locator" xlink:label="arwr_IssuedAtThreeDollarsPerShareMember" />
    <loc xlink:href="arwr-20140331.xsd#arwr_ArrowheadsIncreaseInProportionateShareOfCalandosEquityMember" xlink:type="locator" xlink:label="arwr_ArrowheadsIncreaseInProportionateShareOfCalandosEquityMember" />
    <loc xlink:href="arwr-20140331.xsd#arwr_IssuedAtFiveDollarsAndTwentyCentsPerShareToTelVenturesInExchangeForUnidymSSharesMember" xlink:type="locator" xlink:label="arwr_IssuedAtFiveDollarsAndTwentyCentsPerShareToTelVenturesInExchangeForUnidymSSharesMember" />
    <loc xlink:href="arwr-20140331.xsd#arwr_IssuedAtFiveDollarsAndFiftyCentsPerShareToUnidymStockholderInExchangeForUnidymSSharesMember" xlink:type="locator" xlink:label="arwr_IssuedAtFiveDollarsAndFiftyCentsPerShareToUnidymStockholderInExchangeForUnidymSSharesMember" />
    <loc xlink:href="arwr-20140331.xsd#arwr_IssuedAtTwentyOneDollarsAndEightyCentsPerShareMember" xlink:type="locator" xlink:label="arwr_IssuedAtTwentyOneDollarsAndEightyCentsPerShareMember" />
    <loc xlink:href="arwr-20140331.xsd#arwr_IssuedAtTwentyOneDollarsAndNinetyCentsPerShareToUnidymForAcquisitionOfNanoconductionMember" xlink:type="locator" xlink:label="arwr_IssuedAtTwentyOneDollarsAndNinetyCentsPerShareToUnidymForAcquisitionOfNanoconductionMember" />
    <loc xlink:href="arwr-20140331.xsd#arwr_IssuedAtTwentyNineDollarsAndFiftyCentsPerShareToPurchaseMasaEnergyLlcMember" xlink:type="locator" xlink:label="arwr_IssuedAtTwentyNineDollarsAndFiftyCentsPerShareToPurchaseMasaEnergyLlcMember" />
    <loc xlink:href="arwr-20140331.xsd#arwr_IssuedAtTwentyEightDollarsAndThirtyCentsPerShareToPurchaseSharesOfUnidymIncMember" xlink:type="locator" xlink:label="arwr_IssuedAtTwentyEightDollarsAndThirtyCentsPerShareToPurchaseSharesOfUnidymIncMember" />
    <loc xlink:href="arwr-20140331.xsd#arwr_IssuedAtTwentySevenDollarsAndTwentyCentsPerShareToRiceUniversityMember" xlink:type="locator" xlink:label="arwr_IssuedAtTwentySevenDollarsAndTwentyCentsPerShareToRiceUniversityMember" />
    <loc xlink:href="arwr-20140331.xsd#arwr_IssuedAtApproximatelyEighteenDollarPerShareNetMember" xlink:type="locator" xlink:label="arwr_IssuedAtApproximatelyEighteenDollarPerShareNetMember" />
    <loc xlink:href="arwr-20140331.xsd#arwr_IssuedForPurchaseOfCarbonNanotechnologiesIncAtThirtySevenDollarsAndSeventyCentsPerShareMember" xlink:type="locator" xlink:label="arwr_IssuedForPurchaseOfCarbonNanotechnologiesIncAtThirtySevenDollarsAndSeventyCentsPerShareMember" />
    <loc xlink:href="arwr-20140331.xsd#arwr_IssuedAtFiftySevenDollarsAndEightyCentsPerShareMember" xlink:type="locator" xlink:label="arwr_IssuedAtFiftySevenDollarsAndEightyCentsPerShareMember" />
    <loc xlink:href="arwr-20140331.xsd#arwr_IssuedToPurchaseCalandoPharmaceuticalsIncAtFiftyOneDollarsAndSeventyCentsPerShareMember" xlink:type="locator" xlink:label="arwr_IssuedToPurchaseCalandoPharmaceuticalsIncAtFiftyOneDollarsAndSeventyCentsPerShareMember" />
    <loc xlink:href="arwr-20140331.xsd#arwr_IssuedAtFiftyNineDollarsAndTenCentsPerShareMember" xlink:type="locator" xlink:label="arwr_IssuedAtFiftyNineDollarsAndTenCentsPerShareMember" />
    <loc xlink:href="arwr-20140331.xsd#arwr_IssuedAtThirtyFiveDollarsPerShareMember" xlink:type="locator" xlink:label="arwr_IssuedAtThirtyFiveDollarsPerShareMember" />
    <loc xlink:href="arwr-20140331.xsd#arwr_IssuedAtThirtyEightDollarsAndFortyCentsPerShareMember" xlink:type="locator" xlink:label="arwr_IssuedAtThirtyEightDollarsAndFortyCentsPerShareMember" />
    <loc xlink:href="arwr-20140331.xsd#arwr_IssuedAtFortyEightDollarsAndEightyCentsPerShareMember" xlink:type="locator" xlink:label="arwr_IssuedAtFortyEightDollarsAndEightyCentsPerShareMember" />
    <loc xlink:href="arwr-20140331.xsd#arwr_IssuedToPurchaseInsertTherapeuticsShareAtThirtyNineDollarsAndEightyCentsPerShareMember" xlink:type="locator" xlink:label="arwr_IssuedToPurchaseInsertTherapeuticsShareAtThirtyNineDollarsAndEightyCentsPerShareMember" />
    <loc xlink:href="arwr-20140331.xsd#arwr_ExercisedAtFifteenDollarPerShareMember" xlink:type="locator" xlink:label="arwr_ExercisedAtFifteenDollarPerShareMember" />
    <loc xlink:href="arwr-20140331.xsd#arwr_ExercisedAtTenDollarPerShareMember" xlink:type="locator" xlink:label="arwr_ExercisedAtTenDollarPerShareMember" />
    <loc xlink:href="arwr-20140331.xsd#arwr_ExercisedAtTwoDollarPerShareMember" xlink:type="locator" xlink:label="arwr_ExercisedAtTwoDollarPerShareMember" />
    <loc xlink:href="arwr-20140331.xsd#arwr_IssuedAsStockIssuanceCostAtFifteenDollarPerUnitMember" xlink:type="locator" xlink:label="arwr_IssuedAsStockIssuanceCostAtFifteenDollarPerUnitMember" />
    <loc xlink:href="arwr-20140331.xsd#arwr_IssuedAsGiftForTenDollarAndNinetyCentsPerShareMember" xlink:type="locator" xlink:label="arwr_IssuedAsGiftForTenDollarAndNinetyCentsPerShareMember" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_EquityIssuedInBusinessCombinationMember" xlink:type="locator" xlink:label="us-gaap_EquityIssuedInBusinessCombinationMember" />
    <loc xlink:href="arwr-20140331.xsd#arwr_IssuedForCashAtFifteenDollarPerUnitMember" xlink:type="locator" xlink:label="arwr_IssuedForCashAtFifteenDollarPerUnitMember" />
    <loc xlink:href="arwr-20140331.xsd#arwr_IssuedForMarketableSecuritiesAtTenDollarPerUnitMember" xlink:type="locator" xlink:label="arwr_IssuedForMarketableSecuritiesAtTenDollarPerUnitMember" />
    <loc xlink:href="arwr-20140331.xsd#arwr_StockIssuanceCostChargedToAdditionalPaidInCapitalMember" xlink:type="locator" xlink:label="arwr_StockIssuanceCostChargedToAdditionalPaidInCapitalMember" />
    <loc xlink:href="arwr-20140331.xsd#arwr_IssuedForCashAtTenDollarPerUnitMember" xlink:type="locator" xlink:label="arwr_IssuedForCashAtTenDollarPerUnitMember" />
    <loc xlink:href="arwr-20140331.xsd#arwr_IssuedForCashAtZeroPointZeroOneDollarsPerUnitMember" xlink:type="locator" xlink:label="arwr_IssuedForCashAtZeroPointZeroOneDollarsPerUnitMember" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ClassOfStockDomain" xlink:type="locator" xlink:label="us-gaap_ClassOfStockDomain" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_StatementClassOfStockAxis" xlink:type="locator" xlink:label="us-gaap_StatementClassOfStockAxis" />
    <loc xlink:href="http://xbrl.sec.gov/dei/2013/dei-2013-01-31.xsd#dei_EntityDomain" xlink:type="locator" xlink:label="dei_EntityDomain" />
    <loc xlink:href="http://xbrl.sec.gov/dei/2013/dei-2013-01-31.xsd#dei_LegalEntityAxis" xlink:type="locator" xlink:label="dei_LegalEntityAxis" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_StatementTable" xlink:type="locator" xlink:label="us-gaap_StatementTable" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_StatementOfStockholdersEquityAbstract" xlink:type="locator" xlink:label="us-gaap_StatementOfStockholdersEquityAbstract" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementOfStockholdersEquityAbstract" xlink:to="us-gaap_StatementTable" order="10010.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementTable" xlink:to="dei_LegalEntityAxis" order="10020.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="dei_LegalEntityAxis" xlink:to="dei_EntityDomain" order="10030.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementTable" xlink:to="us-gaap_StatementClassOfStockAxis" order="10020.02" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementClassOfStockAxis" xlink:to="us-gaap_ClassOfStockDomain" order="10050.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfStockDomain" xlink:to="arwr_IssuedForCashAtZeroPointZeroOneDollarsPerUnitMember" order="10070.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfStockDomain" xlink:to="arwr_IssuedForCashAtTenDollarPerUnitMember" order="10110.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfStockDomain" xlink:to="arwr_StockIssuanceCostChargedToAdditionalPaidInCapitalMember" order="10150.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfStockDomain" xlink:to="arwr_IssuedForMarketableSecuritiesAtTenDollarPerUnitMember" order="10210.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfStockDomain" xlink:to="arwr_IssuedForCashAtFifteenDollarPerUnitMember" order="10270.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfStockDomain" xlink:to="us-gaap_EquityIssuedInBusinessCombinationMember" order="10310.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfStockDomain" xlink:to="arwr_IssuedAsGiftForTenDollarAndNinetyCentsPerShareMember" order="10350.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfStockDomain" xlink:to="arwr_IssuedAsStockIssuanceCostAtFifteenDollarPerUnitMember" order="10390.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfStockDomain" xlink:to="arwr_ExercisedAtTwoDollarPerShareMember" order="10430.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfStockDomain" xlink:to="arwr_ExercisedAtTenDollarPerShareMember" order="10470.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfStockDomain" xlink:to="arwr_ExercisedAtFifteenDollarPerShareMember" order="10510.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfStockDomain" xlink:to="arwr_IssuedToPurchaseInsertTherapeuticsShareAtThirtyNineDollarsAndEightyCentsPerShareMember" order="10590.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfStockDomain" xlink:to="arwr_IssuedAtFortyEightDollarsAndEightyCentsPerShareMember" order="10630.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfStockDomain" xlink:to="arwr_IssuedAtThirtyEightDollarsAndFortyCentsPerShareMember" order="10670.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfStockDomain" xlink:to="arwr_IssuedAtThirtyFiveDollarsPerShareMember" order="10710.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfStockDomain" xlink:to="arwr_IssuedAtFiftyNineDollarsAndTenCentsPerShareMember" order="10750.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfStockDomain" xlink:to="arwr_IssuedToPurchaseCalandoPharmaceuticalsIncAtFiftyOneDollarsAndSeventyCentsPerShareMember" order="10790.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfStockDomain" xlink:to="arwr_IssuedAtFiftySevenDollarsAndEightyCentsPerShareMember" order="10830.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfStockDomain" xlink:to="arwr_IssuedForPurchaseOfCarbonNanotechnologiesIncAtThirtySevenDollarsAndSeventyCentsPerShareMember" order="10870.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfStockDomain" xlink:to="arwr_IssuedAtApproximatelyEighteenDollarPerShareNetMember" order="10910.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfStockDomain" xlink:to="arwr_IssuedAtTwentySevenDollarsAndTwentyCentsPerShareToRiceUniversityMember" order="10950.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfStockDomain" xlink:to="arwr_IssuedAtTwentyEightDollarsAndThirtyCentsPerShareToPurchaseSharesOfUnidymIncMember" order="10990.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfStockDomain" xlink:to="arwr_IssuedAtTwentyNineDollarsAndFiftyCentsPerShareToPurchaseMasaEnergyLlcMember" order="11030.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfStockDomain" xlink:to="arwr_IssuedAtTwentyOneDollarsAndNinetyCentsPerShareToUnidymForAcquisitionOfNanoconductionMember" order="11070.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfStockDomain" xlink:to="arwr_IssuedAtTwentyOneDollarsAndEightyCentsPerShareMember" order="11110.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfStockDomain" xlink:to="arwr_IssuedAtFiveDollarsAndFiftyCentsPerShareToUnidymStockholderInExchangeForUnidymSSharesMember" order="11150.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfStockDomain" xlink:to="arwr_IssuedAtFiveDollarsAndTwentyCentsPerShareToTelVenturesInExchangeForUnidymSSharesMember" order="11190.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfStockDomain" xlink:to="arwr_ArrowheadsIncreaseInProportionateShareOfCalandosEquityMember" order="11230.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfStockDomain" xlink:to="arwr_IssuedAtThreeDollarsPerShareMember" order="11250.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfStockDomain" xlink:to="arwr_IssuedToUnidymStockholdersInExchangeForUnidymsSharesMember" order="11290.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfStockDomain" xlink:to="arwr_IssuedAtSixDollarsAndThirtyFourCentsPerShareMember" order="11310.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfStockDomain" xlink:to="arwr_IssuedAtThirteenDollarsAndTwelveCentsPerShareMember" order="11350.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfStockDomain" xlink:to="arwr_IssuedToCalandoStockholdersInExchangeForCalandoSSharesMember" order="11390.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfStockDomain" xlink:to="arwr_IssuedAtThreeDollarsAndEightyCentsPerShareMember" order="11470.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfStockDomain" xlink:to="arwr_IssuanceOfCommonStockForSubscriptionMember" order="11510.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfStockDomain" xlink:to="arwr_IssuedAtThreeDollarsAndSeventyCentsPerShareMember" order="11570.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfStockDomain" xlink:to="arwr_IssuedAtFourDollarsPerShareMember" order="11610.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfStockDomain" xlink:to="arwr_IssuedAtSixDollarsAndTwentyThreeCentsPerShareMember" order="11650.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfStockDomain" xlink:to="arwr_IssuedAtFiveDollarsAndElevenCentsPerShareMember" order="11690.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfStockDomain" xlink:to="arwr_IssuedAtTwoDollarsAndSeventySixCentsPerShareMember" order="11730.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfStockDomain" xlink:to="arwr_IssuedUnderCommittedCapitalAgreementMember" order="11770.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfStockDomain" xlink:to="arwr_PreferredStockIssuedAtThousandDollarsPerShareMember" order="11850.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfStockDomain" xlink:to="arwr_IssuedAtFourDollarsAndFortyNineCentsPerShareMember" order="11910.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfStockDomain" xlink:to="arwr_IssuedAtTwoDollarsAndTwentySixCentsPerShareMember" order="11950.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfStockDomain" xlink:to="arwr_IssuedAtTwoDollarsAndTwelveCentsPerShareMember" order="11990.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfStockDomain" xlink:to="arwr_IssuedAtOneDollarAndEightyThreeCentsPerShareMember" order="12030.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfStockDomain" xlink:to="arwr_IssuedAtFiveDollarsAndEightySixCentsPerShareMember" order="12110.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfStockDomain" xlink:to="arwr_IssuedAtEighteenDollarAndNinetyFiveCentsPerShareMember" order="12150.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfStockDomain" xlink:to="arwr_IssuedToGallowayMember" order="12230.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementTable" xlink:to="us-gaap_StatementEquityComponentsAxis" order="10020.04" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementEquityComponentsAxis" xlink:to="us-gaap_EquityComponentDomain" order="12280.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_EquityComponentDomain" xlink:to="us-gaap_CommonStockMember" order="12300.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_EquityComponentDomain" xlink:to="us-gaap_PreferredStockMember" order="12340.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_EquityComponentDomain" xlink:to="us-gaap_AdditionalPaidInCapitalMember" order="12380.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_EquityComponentDomain" xlink:to="arwr_SubscriptionsReceivableMember" order="12400.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_EquityComponentDomain" xlink:to="us-gaap_AccumulatedDeficitDuringDevelopmentStageMember" order="12420.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_EquityComponentDomain" xlink:to="us-gaap_NoncontrollingInterestMember" order="12440.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementTable" xlink:to="us-gaap_StatementLineItems" order="12460.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest" order="12500.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/periodStartLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_StockIssuedDuringPeriodSharesNewIssues" order="12840.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_StockIssuedDuringPeriodValueNewIssues" order="13060.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_AdjustmentsToAdditionalPaidInCapitalStockIssuedIssuanceCosts" order="13780.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2009/role/negatedLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_ProfitLoss" order="14020.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest_li0l2" order="14260.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/periodEndLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_SharesIssued" order="14540.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/periodEndLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised" order="14760.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_StockIssuedDuringPeriodValueStockOptionsExercised" order="14980.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue" order="19560.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_NoncontrollingInterestIncreaseFromSubsidiaryEquityIssuance" order="22740.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_AdjustmentsToAdditionalPaidInCapitalEquityComponentOfConvertibleDebt" order="35920.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_ProceedsFromIssuanceOfPreferredStockAndPreferenceStock" order="37360.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_AdjustmentsToAdditionalPaidInCapitalConvertibleDebtWithConversionFeature" order="37600.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_NoncontrollingInterestIncreaseFromSaleOfParentEquityInterest" order="39320.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_OtherComprehensiveIncomeLossDerivativesQualifyingAsHedgesNetOfTax" order="40540.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_StockIssuedDuringPeriodSharesReverseStockSplits" order="51280.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2009/role/negatedLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_StockIssuedDuringPeriodSharesConversionOfUnits" order="51980.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_StockIssuedDuringPeriodValueConversionOfUnits" order="52220.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="arwr_SubscriptionReceivable" order="55200.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="arwr_CancellationOfSharesRelatedToSubscriptionReceivables" order="55440.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2009/role/negatedLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="arwr_CancellationOfSubscriptionReceivables" order="55660.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_OtherComprehensiveIncomeUnrealizedGainLossOnDerivativesArisingDuringPeriodNetOfTax" order="57840.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
  </presentationLink>
  <roleRef roleURI="http://www.arrowheadresearch.com/20140331/taxonomy/role/StatementConsolidatedStatementOfStockholdersEquityParenthetical" xlink:href="arwr-20140331.xsd#Role_StatementConsolidatedStatementOfStockholdersEquityParenthetical" xlink:type="simple" />
  <presentationLink xlink:type="extended" xlink:role="http://www.arrowheadresearch.com/20140331/taxonomy/role/StatementConsolidatedStatementOfStockholdersEquityParenthetical">
    <loc xlink:href="arwr-20140331.xsd#arwr_PreferredStockIssuanceValuePerShare" xlink:type="locator" xlink:label="arwr_PreferredStockIssuanceValuePerShare" />
    <loc xlink:href="arwr-20140331.xsd#arwr_CommonStockIssuanceValuePerShare" xlink:type="locator" xlink:label="arwr_CommonStockIssuanceValuePerShare" />
    <loc xlink:href="arwr-20140331.xsd#arwr_ExerciseOfStockOptionsPricePerShare" xlink:type="locator" xlink:label="arwr_ExerciseOfStockOptionsPricePerShare" />
    <loc xlink:href="arwr-20140331.xsd#arwr_CommonStockAndWarrantsIssuedForCashPricePerUnit" xlink:type="locator" xlink:label="arwr_CommonStockAndWarrantsIssuedForCashPricePerUnit" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_StatementLineItems" xlink:type="locator" xlink:label="us-gaap_StatementLineItems" />
    <loc xlink:href="arwr-20140331.xsd#arwr_IssuedAtEighteenDollarAndNinetyFiveCentsPerShareMember" xlink:type="locator" xlink:label="arwr_IssuedAtEighteenDollarAndNinetyFiveCentsPerShareMember" />
    <loc xlink:href="arwr-20140331.xsd#arwr_IssuedAtFiveDollarsAndEightySixCentsPerShareMember" xlink:type="locator" xlink:label="arwr_IssuedAtFiveDollarsAndEightySixCentsPerShareMember" />
    <loc xlink:href="arwr-20140331.xsd#arwr_IssuedAtOneDollarAndEightyThreeCentsPerShareMember" xlink:type="locator" xlink:label="arwr_IssuedAtOneDollarAndEightyThreeCentsPerShareMember" />
    <loc xlink:href="arwr-20140331.xsd#arwr_IssuedAtTwoDollarsAndTwelveCentsPerShareMember" xlink:type="locator" xlink:label="arwr_IssuedAtTwoDollarsAndTwelveCentsPerShareMember" />
    <loc xlink:href="arwr-20140331.xsd#arwr_IssuedAtTwoDollarsAndTwentySixCentsPerShareMember" xlink:type="locator" xlink:label="arwr_IssuedAtTwoDollarsAndTwentySixCentsPerShareMember" />
    <loc xlink:href="arwr-20140331.xsd#arwr_IssuedAtFourDollarsAndFortyNineCentsPerShareMember" xlink:type="locator" xlink:label="arwr_IssuedAtFourDollarsAndFortyNineCentsPerShareMember" />
    <loc xlink:href="arwr-20140331.xsd#arwr_PreferredStockIssuedAtThousandDollarsPerShareMember" xlink:type="locator" xlink:label="arwr_PreferredStockIssuedAtThousandDollarsPerShareMember" />
    <loc xlink:href="arwr-20140331.xsd#arwr_IssuedAtTwoDollarsAndSeventySixCentsPerShareMember" xlink:type="locator" xlink:label="arwr_IssuedAtTwoDollarsAndSeventySixCentsPerShareMember" />
    <loc xlink:href="arwr-20140331.xsd#arwr_IssuedAtFiveDollarsAndElevenCentsPerShareMember" xlink:type="locator" xlink:label="arwr_IssuedAtFiveDollarsAndElevenCentsPerShareMember" />
    <loc xlink:href="arwr-20140331.xsd#arwr_IssuedAtSixDollarsAndTwentyThreeCentsPerShareMember" xlink:type="locator" xlink:label="arwr_IssuedAtSixDollarsAndTwentyThreeCentsPerShareMember" />
    <loc xlink:href="arwr-20140331.xsd#arwr_IssuedAtFourDollarsPerShareMember" xlink:type="locator" xlink:label="arwr_IssuedAtFourDollarsPerShareMember" />
    <loc xlink:href="arwr-20140331.xsd#arwr_IssuedAtThreeDollarsAndSeventyCentsPerShareMember" xlink:type="locator" xlink:label="arwr_IssuedAtThreeDollarsAndSeventyCentsPerShareMember" />
    <loc xlink:href="arwr-20140331.xsd#arwr_IssuedAtThreeDollarsAndEightyCentsPerShareMember" xlink:type="locator" xlink:label="arwr_IssuedAtThreeDollarsAndEightyCentsPerShareMember" />
    <loc xlink:href="arwr-20140331.xsd#arwr_IssuedAtThirteenDollarsAndTwelveCentsPerShareMember" xlink:type="locator" xlink:label="arwr_IssuedAtThirteenDollarsAndTwelveCentsPerShareMember" />
    <loc xlink:href="arwr-20140331.xsd#arwr_IssuedAtSixDollarsAndThirtyFourCentsPerShareMember" xlink:type="locator" xlink:label="arwr_IssuedAtSixDollarsAndThirtyFourCentsPerShareMember" />
    <loc xlink:href="arwr-20140331.xsd#arwr_IssuedAtThreeDollarsPerShareMember" xlink:type="locator" xlink:label="arwr_IssuedAtThreeDollarsPerShareMember" />
    <loc xlink:href="arwr-20140331.xsd#arwr_IssuedAtFiveDollarsAndTwentyCentsPerShareToTelVenturesInExchangeForUnidymSSharesMember" xlink:type="locator" xlink:label="arwr_IssuedAtFiveDollarsAndTwentyCentsPerShareToTelVenturesInExchangeForUnidymSSharesMember" />
    <loc xlink:href="arwr-20140331.xsd#arwr_IssuedAtFiveDollarsAndFiftyCentsPerShareToUnidymStockholderInExchangeForUnidymSSharesMember" xlink:type="locator" xlink:label="arwr_IssuedAtFiveDollarsAndFiftyCentsPerShareToUnidymStockholderInExchangeForUnidymSSharesMember" />
    <loc xlink:href="arwr-20140331.xsd#arwr_IssuedAtTwentyOneDollarsAndEightyCentsPerShareMember" xlink:type="locator" xlink:label="arwr_IssuedAtTwentyOneDollarsAndEightyCentsPerShareMember" />
    <loc xlink:href="arwr-20140331.xsd#arwr_IssuedAtTwentyOneDollarsAndNinetyCentsPerShareToUnidymForAcquisitionOfNanoconductionMember" xlink:type="locator" xlink:label="arwr_IssuedAtTwentyOneDollarsAndNinetyCentsPerShareToUnidymForAcquisitionOfNanoconductionMember" />
    <loc xlink:href="arwr-20140331.xsd#arwr_IssuedAtTwentyNineDollarsAndFiftyCentsPerShareToPurchaseMasaEnergyLlcMember" xlink:type="locator" xlink:label="arwr_IssuedAtTwentyNineDollarsAndFiftyCentsPerShareToPurchaseMasaEnergyLlcMember" />
    <loc xlink:href="arwr-20140331.xsd#arwr_IssuedAtTwentyEightDollarsAndThirtyCentsPerShareToPurchaseSharesOfUnidymIncMember" xlink:type="locator" xlink:label="arwr_IssuedAtTwentyEightDollarsAndThirtyCentsPerShareToPurchaseSharesOfUnidymIncMember" />
    <loc xlink:href="arwr-20140331.xsd#arwr_IssuedAtTwentySevenDollarsAndTwentyCentsPerShareToRiceUniversityMember" xlink:type="locator" xlink:label="arwr_IssuedAtTwentySevenDollarsAndTwentyCentsPerShareToRiceUniversityMember" />
    <loc xlink:href="arwr-20140331.xsd#arwr_IssuedAtApproximatelyEighteenDollarPerShareNetMember" xlink:type="locator" xlink:label="arwr_IssuedAtApproximatelyEighteenDollarPerShareNetMember" />
    <loc xlink:href="arwr-20140331.xsd#arwr_IssuedForPurchaseOfCarbonNanotechnologiesIncAtThirtySevenDollarsAndSeventyCentsPerShareMember" xlink:type="locator" xlink:label="arwr_IssuedForPurchaseOfCarbonNanotechnologiesIncAtThirtySevenDollarsAndSeventyCentsPerShareMember" />
    <loc xlink:href="arwr-20140331.xsd#arwr_IssuedAtFiftySevenDollarsAndEightyCentsPerShareMember" xlink:type="locator" xlink:label="arwr_IssuedAtFiftySevenDollarsAndEightyCentsPerShareMember" />
    <loc xlink:href="arwr-20140331.xsd#arwr_IssuedToPurchaseCalandoPharmaceuticalsIncAtFiftyOneDollarsAndSeventyCentsPerShareMember" xlink:type="locator" xlink:label="arwr_IssuedToPurchaseCalandoPharmaceuticalsIncAtFiftyOneDollarsAndSeventyCentsPerShareMember" />
    <loc xlink:href="arwr-20140331.xsd#arwr_IssuedAtFiftyNineDollarsAndTenCentsPerShareMember" xlink:type="locator" xlink:label="arwr_IssuedAtFiftyNineDollarsAndTenCentsPerShareMember" />
    <loc xlink:href="arwr-20140331.xsd#arwr_IssuedAtThirtyFiveDollarsPerShareMember" xlink:type="locator" xlink:label="arwr_IssuedAtThirtyFiveDollarsPerShareMember" />
    <loc xlink:href="arwr-20140331.xsd#arwr_IssuedAtThirtyEightDollarsAndFortyCentsPerShareMember" xlink:type="locator" xlink:label="arwr_IssuedAtThirtyEightDollarsAndFortyCentsPerShareMember" />
    <loc xlink:href="arwr-20140331.xsd#arwr_IssuedAtFortyEightDollarsAndEightyCentsPerShareMember" xlink:type="locator" xlink:label="arwr_IssuedAtFortyEightDollarsAndEightyCentsPerShareMember" />
    <loc xlink:href="arwr-20140331.xsd#arwr_IssuedToPurchaseInsertTherapeuticsShareAtThirtyNineDollarsAndEightyCentsPerShareMember" xlink:type="locator" xlink:label="arwr_IssuedToPurchaseInsertTherapeuticsShareAtThirtyNineDollarsAndEightyCentsPerShareMember" />
    <loc xlink:href="arwr-20140331.xsd#arwr_ExercisedAtFifteenDollarPerShareMember" xlink:type="locator" xlink:label="arwr_ExercisedAtFifteenDollarPerShareMember" />
    <loc xlink:href="arwr-20140331.xsd#arwr_ExercisedAtTenDollarPerShareMember" xlink:type="locator" xlink:label="arwr_ExercisedAtTenDollarPerShareMember" />
    <loc xlink:href="arwr-20140331.xsd#arwr_ExercisedAtTwoDollarPerShareMember" xlink:type="locator" xlink:label="arwr_ExercisedAtTwoDollarPerShareMember" />
    <loc xlink:href="arwr-20140331.xsd#arwr_IssuedAsStockIssuanceCostAtFifteenDollarPerUnitMember" xlink:type="locator" xlink:label="arwr_IssuedAsStockIssuanceCostAtFifteenDollarPerUnitMember" />
    <loc xlink:href="arwr-20140331.xsd#arwr_IssuedAsGiftForTenDollarAndNinetyCentsPerShareMember" xlink:type="locator" xlink:label="arwr_IssuedAsGiftForTenDollarAndNinetyCentsPerShareMember" />
    <loc xlink:href="arwr-20140331.xsd#arwr_IssuedForCashAtFifteenDollarPerUnitMember" xlink:type="locator" xlink:label="arwr_IssuedForCashAtFifteenDollarPerUnitMember" />
    <loc xlink:href="arwr-20140331.xsd#arwr_IssuedForMarketableSecuritiesAtTenDollarPerUnitMember" xlink:type="locator" xlink:label="arwr_IssuedForMarketableSecuritiesAtTenDollarPerUnitMember" />
    <loc xlink:href="arwr-20140331.xsd#arwr_IssuedForCashAtTenDollarPerUnitMember" xlink:type="locator" xlink:label="arwr_IssuedForCashAtTenDollarPerUnitMember" />
    <loc xlink:href="arwr-20140331.xsd#arwr_IssuedForCashAtZeroPointZeroOneDollarsPerUnitMember" xlink:type="locator" xlink:label="arwr_IssuedForCashAtZeroPointZeroOneDollarsPerUnitMember" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ClassOfStockDomain" xlink:type="locator" xlink:label="us-gaap_ClassOfStockDomain" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_StatementClassOfStockAxis" xlink:type="locator" xlink:label="us-gaap_StatementClassOfStockAxis" />
    <loc xlink:href="http://xbrl.sec.gov/dei/2013/dei-2013-01-31.xsd#dei_EntityDomain" xlink:type="locator" xlink:label="dei_EntityDomain" />
    <loc xlink:href="http://xbrl.sec.gov/dei/2013/dei-2013-01-31.xsd#dei_LegalEntityAxis" xlink:type="locator" xlink:label="dei_LegalEntityAxis" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_StatementTable" xlink:type="locator" xlink:label="us-gaap_StatementTable" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_StatementOfStockholdersEquityAbstract" xlink:type="locator" xlink:label="us-gaap_StatementOfStockholdersEquityAbstract" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementOfStockholdersEquityAbstract" xlink:to="us-gaap_StatementTable" order="10010.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementTable" xlink:to="dei_LegalEntityAxis" order="10020.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="dei_LegalEntityAxis" xlink:to="dei_EntityDomain" order="10030.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementTable" xlink:to="us-gaap_StatementClassOfStockAxis" order="10020.02" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementClassOfStockAxis" xlink:to="us-gaap_ClassOfStockDomain" order="10050.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfStockDomain" xlink:to="arwr_IssuedForCashAtZeroPointZeroOneDollarsPerUnitMember" order="10070.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfStockDomain" xlink:to="arwr_IssuedForCashAtTenDollarPerUnitMember" order="10090.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfStockDomain" xlink:to="arwr_IssuedForMarketableSecuritiesAtTenDollarPerUnitMember" order="10130.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfStockDomain" xlink:to="arwr_IssuedForCashAtFifteenDollarPerUnitMember" order="10150.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfStockDomain" xlink:to="arwr_IssuedAsGiftForTenDollarAndNinetyCentsPerShareMember" order="10170.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfStockDomain" xlink:to="arwr_IssuedAsStockIssuanceCostAtFifteenDollarPerUnitMember" order="10190.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfStockDomain" xlink:to="arwr_ExercisedAtTwoDollarPerShareMember" order="10210.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfStockDomain" xlink:to="arwr_ExercisedAtTenDollarPerShareMember" order="10230.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfStockDomain" xlink:to="arwr_ExercisedAtFifteenDollarPerShareMember" order="10250.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfStockDomain" xlink:to="arwr_IssuedToPurchaseInsertTherapeuticsShareAtThirtyNineDollarsAndEightyCentsPerShareMember" order="10290.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfStockDomain" xlink:to="arwr_IssuedAtFortyEightDollarsAndEightyCentsPerShareMember" order="10310.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfStockDomain" xlink:to="arwr_IssuedAtThirtyEightDollarsAndFortyCentsPerShareMember" order="10330.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfStockDomain" xlink:to="arwr_IssuedAtThirtyFiveDollarsPerShareMember" order="10350.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfStockDomain" xlink:to="arwr_IssuedAtFiftyNineDollarsAndTenCentsPerShareMember" order="10370.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfStockDomain" xlink:to="arwr_IssuedToPurchaseCalandoPharmaceuticalsIncAtFiftyOneDollarsAndSeventyCentsPerShareMember" order="10390.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfStockDomain" xlink:to="arwr_IssuedAtFiftySevenDollarsAndEightyCentsPerShareMember" order="10410.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfStockDomain" xlink:to="arwr_IssuedForPurchaseOfCarbonNanotechnologiesIncAtThirtySevenDollarsAndSeventyCentsPerShareMember" order="10430.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfStockDomain" xlink:to="arwr_IssuedAtApproximatelyEighteenDollarPerShareNetMember" order="10450.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfStockDomain" xlink:to="arwr_IssuedAtTwentySevenDollarsAndTwentyCentsPerShareToRiceUniversityMember" order="10470.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfStockDomain" xlink:to="arwr_IssuedAtTwentyEightDollarsAndThirtyCentsPerShareToPurchaseSharesOfUnidymIncMember" order="10490.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfStockDomain" xlink:to="arwr_IssuedAtTwentyNineDollarsAndFiftyCentsPerShareToPurchaseMasaEnergyLlcMember" order="10510.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfStockDomain" xlink:to="arwr_IssuedAtTwentyOneDollarsAndNinetyCentsPerShareToUnidymForAcquisitionOfNanoconductionMember" order="10530.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfStockDomain" xlink:to="arwr_IssuedAtTwentyOneDollarsAndEightyCentsPerShareMember" order="10550.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfStockDomain" xlink:to="arwr_IssuedAtFiveDollarsAndFiftyCentsPerShareToUnidymStockholderInExchangeForUnidymSSharesMember" order="10570.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfStockDomain" xlink:to="arwr_IssuedAtFiveDollarsAndTwentyCentsPerShareToTelVenturesInExchangeForUnidymSSharesMember" order="10590.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfStockDomain" xlink:to="arwr_IssuedAtThreeDollarsPerShareMember" order="10610.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfStockDomain" xlink:to="arwr_IssuedAtSixDollarsAndThirtyFourCentsPerShareMember" order="10630.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfStockDomain" xlink:to="arwr_IssuedAtThirteenDollarsAndTwelveCentsPerShareMember" order="10650.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfStockDomain" xlink:to="arwr_IssuedAtThreeDollarsAndEightyCentsPerShareMember" order="10670.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfStockDomain" xlink:to="arwr_IssuedAtThreeDollarsAndSeventyCentsPerShareMember" order="10710.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfStockDomain" xlink:to="arwr_IssuedAtFourDollarsPerShareMember" order="10730.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfStockDomain" xlink:to="arwr_IssuedAtSixDollarsAndTwentyThreeCentsPerShareMember" order="10750.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfStockDomain" xlink:to="arwr_IssuedAtFiveDollarsAndElevenCentsPerShareMember" order="10770.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfStockDomain" xlink:to="arwr_IssuedAtTwoDollarsAndSeventySixCentsPerShareMember" order="10790.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfStockDomain" xlink:to="arwr_PreferredStockIssuedAtThousandDollarsPerShareMember" order="10810.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfStockDomain" xlink:to="arwr_IssuedAtFourDollarsAndFortyNineCentsPerShareMember" order="10830.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfStockDomain" xlink:to="arwr_IssuedAtTwoDollarsAndTwentySixCentsPerShareMember" order="10850.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfStockDomain" xlink:to="arwr_IssuedAtTwoDollarsAndTwelveCentsPerShareMember" order="10870.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfStockDomain" xlink:to="arwr_IssuedAtOneDollarAndEightyThreeCentsPerShareMember" order="10890.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfStockDomain" xlink:to="arwr_IssuedAtFiveDollarsAndEightySixCentsPerShareMember" order="10930.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfStockDomain" xlink:to="arwr_IssuedAtEighteenDollarAndNinetyFiveCentsPerShareMember" order="10950.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementTable" xlink:to="us-gaap_StatementLineItems" order="10990.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="arwr_CommonStockAndWarrantsIssuedForCashPricePerUnit" order="11030.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="arwr_ExerciseOfStockOptionsPricePerShare" order="11450.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="arwr_CommonStockIssuanceValuePerShare" order="11690.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="arwr_PreferredStockIssuanceValuePerShare" order="13250.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
  </presentationLink>
  <roleRef roleURI="http://www.arrowheadresearch.com/20140331/taxonomy/role/StatementConsolidatedStatementsOfCashFlows" xlink:href="arwr-20140331.xsd#Role_StatementConsolidatedStatementsOfCashFlows" xlink:type="simple" />
  <presentationLink xlink:type="extended" xlink:role="http://www.arrowheadresearch.com/20140331/taxonomy/role/StatementConsolidatedStatementsOfCashFlows">
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_IncomeTaxesPaid" xlink:type="locator" xlink:label="us-gaap_IncomeTaxesPaid" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_InterestPaid" xlink:type="locator" xlink:label="us-gaap_InterestPaid" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_SupplementalCashFlowInformationAbstract" xlink:type="locator" xlink:label="us-gaap_SupplementalCashFlowInformationAbstract" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_CashAndCashEquivalentsAtCarryingValue" xlink:type="locator" xlink:label="us-gaap_CashAndCashEquivalentsAtCarryingValue_li0l2" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_CashAndCashEquivalentsAtCarryingValue" xlink:type="locator" xlink:label="us-gaap_CashAndCashEquivalentsAtCarryingValue" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_CashAndCashEquivalentsPeriodIncreaseDecrease" xlink:type="locator" xlink:label="us-gaap_CashAndCashEquivalentsPeriodIncreaseDecrease" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_NetCashProvidedByUsedInDiscontinuedOperations" xlink:type="locator" xlink:label="us-gaap_NetCashProvidedByUsedInDiscontinuedOperations" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_CashProvidedByUsedInFinancingActivitiesDiscontinuedOperations" xlink:type="locator" xlink:label="us-gaap_CashProvidedByUsedInFinancingActivitiesDiscontinuedOperations" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_CashProvidedByUsedInInvestingActivitiesDiscontinuedOperations" xlink:type="locator" xlink:label="us-gaap_CashProvidedByUsedInInvestingActivitiesDiscontinuedOperations" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_CashProvidedByUsedInOperatingActivitiesDiscontinuedOperations" xlink:type="locator" xlink:label="us-gaap_CashProvidedByUsedInOperatingActivitiesDiscontinuedOperations" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_NetCashProvidedByUsedInDiscontinuedOperationsAbstract" xlink:type="locator" xlink:label="us-gaap_NetCashProvidedByUsedInDiscontinuedOperationsAbstract" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_NetCashProvidedByUsedInFinancingActivitiesContinuingOperations" xlink:type="locator" xlink:label="us-gaap_NetCashProvidedByUsedInFinancingActivitiesContinuingOperations" />
    <loc xlink:href="arwr-20140331.xsd#arwr_ProceedsFromSaleOfStockInSubsidiary" xlink:type="locator" xlink:label="arwr_ProceedsFromSaleOfStockInSubsidiary" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ProceedsFromIssuanceOfLongTermDebt" xlink:type="locator" xlink:label="us-gaap_ProceedsFromIssuanceOfLongTermDebt" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ProceedsFromIssuanceOfCommonStock" xlink:type="locator" xlink:label="us-gaap_ProceedsFromIssuanceOfCommonStock" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_RepaymentsOfLongTermCapitalLeaseObligations" xlink:type="locator" xlink:label="us-gaap_RepaymentsOfLongTermCapitalLeaseObligations" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_NetCashProvidedByUsedInFinancingActivitiesContinuingOperationsAbstract" xlink:type="locator" xlink:label="us-gaap_NetCashProvidedByUsedInFinancingActivitiesContinuingOperationsAbstract" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_NetCashProvidedByUsedInInvestingActivitiesContinuingOperations" xlink:type="locator" xlink:label="us-gaap_NetCashProvidedByUsedInInvestingActivitiesContinuingOperations" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_IncreaseDecreaseInRestrictedCash" xlink:type="locator" xlink:label="us-gaap_IncreaseDecreaseInRestrictedCash" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_PaymentsToAcquireIntangibleAssets" xlink:type="locator" xlink:label="us-gaap_PaymentsToAcquireIntangibleAssets" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ProceedsFromDivestitureOfInterestInConsolidatedSubsidiaries" xlink:type="locator" xlink:label="us-gaap_ProceedsFromDivestitureOfInterestInConsolidatedSubsidiaries" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ProceedsFromDivestitureOfInterestInSubsidiariesAndAffiliates" xlink:type="locator" xlink:label="us-gaap_ProceedsFromDivestitureOfInterestInSubsidiariesAndAffiliates" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_PaymentsToAcquireInterestInSubsidiariesAndAffiliates" xlink:type="locator" xlink:label="us-gaap_PaymentsToAcquireInterestInSubsidiariesAndAffiliates" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_PaymentsToAcquireAdditionalInterestInSubsidiaries" xlink:type="locator" xlink:label="us-gaap_PaymentsToAcquireAdditionalInterestInSubsidiaries" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_PaymentsToAcquireBusinessesNetOfCashAcquired" xlink:type="locator" xlink:label="us-gaap_PaymentsToAcquireBusinessesNetOfCashAcquired" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_CashDivestedFromDeconsolidation" xlink:type="locator" xlink:label="us-gaap_CashDivestedFromDeconsolidation" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ProceedsFromSaleAndMaturityOfMarketableSecurities" xlink:type="locator" xlink:label="us-gaap_ProceedsFromSaleAndMaturityOfMarketableSecurities" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_PaymentsToAcquireMarketableSecurities" xlink:type="locator" xlink:label="us-gaap_PaymentsToAcquireMarketableSecurities" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ProceedsFromSaleOfPropertyPlantAndEquipment" xlink:type="locator" xlink:label="us-gaap_ProceedsFromSaleOfPropertyPlantAndEquipment" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ProceedsFromSaleMaturityAndCollectionsOfInvestments" xlink:type="locator" xlink:label="us-gaap_ProceedsFromSaleMaturityAndCollectionsOfInvestments" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_PaymentsToAcquirePropertyPlantAndEquipment" xlink:type="locator" xlink:label="us-gaap_PaymentsToAcquirePropertyPlantAndEquipment" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_NetCashProvidedByUsedInInvestingActivitiesContinuingOperationsAbstract" xlink:type="locator" xlink:label="us-gaap_NetCashProvidedByUsedInInvestingActivitiesContinuingOperationsAbstract" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_NetCashProvidedByUsedInOperatingActivitiesContinuingOperations" xlink:type="locator" xlink:label="us-gaap_NetCashProvidedByUsedInOperatingActivitiesContinuingOperations" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_IncreaseDecreaseInOtherOperatingLiabilities" xlink:type="locator" xlink:label="us-gaap_IncreaseDecreaseInOtherOperatingLiabilities" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_IncreaseDecreaseInAccruedLiabilities" xlink:type="locator" xlink:label="us-gaap_IncreaseDecreaseInAccruedLiabilities" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_IncreaseDecreaseInAccountsPayable" xlink:type="locator" xlink:label="us-gaap_IncreaseDecreaseInAccountsPayable" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_IncreaseDecreaseInOtherOperatingAssets" xlink:type="locator" xlink:label="us-gaap_IncreaseDecreaseInOtherOperatingAssets" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_IncreaseDecreaseInPrepaidExpense" xlink:type="locator" xlink:label="us-gaap_IncreaseDecreaseInPrepaidExpense" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_IncreaseDecreaseInOtherReceivables" xlink:type="locator" xlink:label="us-gaap_IncreaseDecreaseInOtherReceivables" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_IncreaseDecreaseInReceivables" xlink:type="locator" xlink:label="us-gaap_IncreaseDecreaseInReceivables" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_IncreaseDecreaseInOperatingCapitalAbstract" xlink:type="locator" xlink:label="us-gaap_IncreaseDecreaseInOperatingCapitalAbstract" />
    <loc xlink:href="arwr-20140331.xsd#arwr_NoncontrollingInterest" xlink:type="locator" xlink:label="arwr_NoncontrollingInterest" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_GainLossOnSaleOfEquityInvestments" xlink:type="locator" xlink:label="us-gaap_GainLossOnSaleOfEquityInvestments" />
    <loc xlink:href="arwr-20140331.xsd#arwr_NonCashImpairmentCharges" xlink:type="locator" xlink:label="arwr_NonCashImpairmentCharges" />
    <loc xlink:href="arwr-20140331.xsd#arwr_GainLossOnSaleOfStockInSubsidiary" xlink:type="locator" xlink:label="arwr_GainLossOnSaleOfStockInSubsidiary" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_AmortizationOfDebtDiscountPremium" xlink:type="locator" xlink:label="us-gaap_AmortizationOfDebtDiscountPremium" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DepreciationDepletionAndAmortization" xlink:type="locator" xlink:label="us-gaap_DepreciationDepletionAndAmortization" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ShareBasedCompensation" xlink:type="locator" xlink:label="us-gaap_ShareBasedCompensation" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ResearchAndDevelopmentInProcess" xlink:type="locator" xlink:label="us-gaap_ResearchAndDevelopmentInProcess" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_BusinessCombinationContingentConsiderationArrangementsChangeInAmountOfContingentConsiderationLiability1" xlink:type="locator" xlink:label="us-gaap_BusinessCombinationContingentConsiderationArrangementsChangeInAmountOfContingentConsiderationLiability1" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_UnrealizedGainLossOnDerivatives" xlink:type="locator" xlink:label="us-gaap_UnrealizedGainLossOnDerivatives" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_IssuanceOfStockAndWarrantsForServicesOrClaims" xlink:type="locator" xlink:label="us-gaap_IssuanceOfStockAndWarrantsForServicesOrClaims" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_GainLossOnSaleOfPropertyPlantEquipment" xlink:type="locator" xlink:label="us-gaap_GainLossOnSaleOfPropertyPlantEquipment" />
    <loc xlink:href="arwr-20140331.xsd#arwr_GainOnAcquisition" xlink:type="locator" xlink:label="arwr_GainOnAcquisition" />
    <loc xlink:href="arwr-20140331.xsd#arwr_GainLossFromSaleOfSubsidiary" xlink:type="locator" xlink:label="arwr_GainLossFromSaleOfSubsidiary" />
    <loc xlink:href="arwr-20140331.xsd#arwr_ProvisionForAllowanceForBadDebtsAndSalesRelatedAllowances" xlink:type="locator" xlink:label="arwr_ProvisionForAllowanceForBadDebtsAndSalesRelatedAllowances" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_GainLossOnSaleOfInvestments" xlink:type="locator" xlink:label="us-gaap_GainLossOnSaleOfInvestments" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DiscontinuedOperationIncomeLossFromDiscontinuedOperationBeforeIncomeTax" xlink:type="locator" xlink:label="us-gaap_DiscontinuedOperationIncomeLossFromDiscontinuedOperationBeforeIncomeTax" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_NetIncomeLoss" xlink:type="locator" xlink:label="us-gaap_NetIncomeLoss" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_NetIncomeLossAttributableToNoncontrollingInterest" xlink:type="locator" xlink:label="us-gaap_NetIncomeLossAttributableToNoncontrollingInterest" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ProfitLoss" xlink:type="locator" xlink:label="us-gaap_ProfitLoss" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_NetCashProvidedByUsedInOperatingActivitiesContinuingOperationsAbstract" xlink:type="locator" xlink:label="us-gaap_NetCashProvidedByUsedInOperatingActivitiesContinuingOperationsAbstract" />
    <loc xlink:href="arwr-20140331.xsd#arwr_StatementConsolidatedStatementsOfCashFlowsLineItems" xlink:type="locator" xlink:label="arwr_StatementConsolidatedStatementsOfCashFlowsLineItems" />
    <loc xlink:href="http://xbrl.sec.gov/dei/2013/dei-2013-01-31.xsd#dei_EntityDomain" xlink:type="locator" xlink:label="dei_EntityDomain" />
    <loc xlink:href="http://xbrl.sec.gov/dei/2013/dei-2013-01-31.xsd#dei_LegalEntityAxis" xlink:type="locator" xlink:label="dei_LegalEntityAxis" />
    <loc xlink:href="arwr-20140331.xsd#arwr_StatementConsolidatedStatementsOfCashFlowsTable" xlink:type="locator" xlink:label="arwr_StatementConsolidatedStatementsOfCashFlowsTable" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_StatementOfCashFlowsAbstract" xlink:type="locator" xlink:label="us-gaap_StatementOfCashFlowsAbstract" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementOfCashFlowsAbstract" xlink:to="arwr_StatementConsolidatedStatementsOfCashFlowsTable" order="10500.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="arwr_StatementConsolidatedStatementsOfCashFlowsTable" xlink:to="dei_LegalEntityAxis" order="10510.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="dei_LegalEntityAxis" xlink:to="dei_EntityDomain" order="10520.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="arwr_StatementConsolidatedStatementsOfCashFlowsTable" xlink:to="arwr_StatementConsolidatedStatementsOfCashFlowsLineItems" order="10530.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="arwr_StatementConsolidatedStatementsOfCashFlowsLineItems" xlink:to="us-gaap_NetCashProvidedByUsedInOperatingActivitiesContinuingOperationsAbstract" order="10570.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_NetCashProvidedByUsedInOperatingActivitiesContinuingOperationsAbstract" xlink:to="us-gaap_ProfitLoss" order="10690.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_NetCashProvidedByUsedInOperatingActivitiesContinuingOperationsAbstract" xlink:to="us-gaap_NetIncomeLossAttributableToNoncontrollingInterest" order="10750.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2009/role/negatedLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_NetCashProvidedByUsedInOperatingActivitiesContinuingOperationsAbstract" xlink:to="us-gaap_NetIncomeLoss" order="10810.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/totalLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_NetCashProvidedByUsedInOperatingActivitiesContinuingOperationsAbstract" xlink:to="us-gaap_DiscontinuedOperationIncomeLossFromDiscontinuedOperationBeforeIncomeTax" order="10870.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2009/role/negatedLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_NetCashProvidedByUsedInOperatingActivitiesContinuingOperationsAbstract" xlink:to="us-gaap_GainLossOnSaleOfInvestments" order="10970.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2009/role/negatedLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_NetCashProvidedByUsedInOperatingActivitiesContinuingOperationsAbstract" xlink:to="arwr_ProvisionForAllowanceForBadDebtsAndSalesRelatedAllowances" order="11050.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_NetCashProvidedByUsedInOperatingActivitiesContinuingOperationsAbstract" xlink:to="arwr_GainLossFromSaleOfSubsidiary" order="11130.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2009/role/negatedLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_NetCashProvidedByUsedInOperatingActivitiesContinuingOperationsAbstract" xlink:to="arwr_GainOnAcquisition" order="11210.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2009/role/negatedLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_NetCashProvidedByUsedInOperatingActivitiesContinuingOperationsAbstract" xlink:to="us-gaap_GainLossOnSaleOfPropertyPlantEquipment" order="11270.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2009/role/negatedLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_NetCashProvidedByUsedInOperatingActivitiesContinuingOperationsAbstract" xlink:to="us-gaap_IssuanceOfStockAndWarrantsForServicesOrClaims" order="11330.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_NetCashProvidedByUsedInOperatingActivitiesContinuingOperationsAbstract" xlink:to="us-gaap_UnrealizedGainLossOnDerivatives" order="11410.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2009/role/negatedLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_NetCashProvidedByUsedInOperatingActivitiesContinuingOperationsAbstract" xlink:to="us-gaap_BusinessCombinationContingentConsiderationArrangementsChangeInAmountOfContingentConsiderationLiability1" order="11470.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_NetCashProvidedByUsedInOperatingActivitiesContinuingOperationsAbstract" xlink:to="us-gaap_ResearchAndDevelopmentInProcess" order="11530.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_NetCashProvidedByUsedInOperatingActivitiesContinuingOperationsAbstract" xlink:to="us-gaap_ShareBasedCompensation" order="11610.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_NetCashProvidedByUsedInOperatingActivitiesContinuingOperationsAbstract" xlink:to="us-gaap_DepreciationDepletionAndAmortization" order="11670.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_NetCashProvidedByUsedInOperatingActivitiesContinuingOperationsAbstract" xlink:to="us-gaap_AmortizationOfDebtDiscountPremium" order="11730.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_NetCashProvidedByUsedInOperatingActivitiesContinuingOperationsAbstract" xlink:to="arwr_GainLossOnSaleOfStockInSubsidiary" order="11850.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2009/role/negatedLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_NetCashProvidedByUsedInOperatingActivitiesContinuingOperationsAbstract" xlink:to="arwr_NonCashImpairmentCharges" order="11910.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_NetCashProvidedByUsedInOperatingActivitiesContinuingOperationsAbstract" xlink:to="us-gaap_GainLossOnSaleOfEquityInvestments" order="12010.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2009/role/negatedLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_NetCashProvidedByUsedInOperatingActivitiesContinuingOperationsAbstract" xlink:to="arwr_NoncontrollingInterest" order="12110.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2009/role/negatedLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_NetCashProvidedByUsedInOperatingActivitiesContinuingOperationsAbstract" xlink:to="us-gaap_IncreaseDecreaseInOperatingCapitalAbstract" order="12230.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_IncreaseDecreaseInOperatingCapitalAbstract" xlink:to="us-gaap_IncreaseDecreaseInReceivables" order="12350.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2009/role/negatedLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_IncreaseDecreaseInOperatingCapitalAbstract" xlink:to="us-gaap_IncreaseDecreaseInOtherReceivables" order="12470.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2009/role/negatedLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_IncreaseDecreaseInOperatingCapitalAbstract" xlink:to="us-gaap_IncreaseDecreaseInPrepaidExpense" order="12590.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2009/role/negatedLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_IncreaseDecreaseInOperatingCapitalAbstract" xlink:to="us-gaap_IncreaseDecreaseInOtherOperatingAssets" order="12710.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2009/role/negatedLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_IncreaseDecreaseInOperatingCapitalAbstract" xlink:to="us-gaap_IncreaseDecreaseInAccountsPayable" order="12830.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_IncreaseDecreaseInOperatingCapitalAbstract" xlink:to="us-gaap_IncreaseDecreaseInAccruedLiabilities" order="12950.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_IncreaseDecreaseInOperatingCapitalAbstract" xlink:to="us-gaap_IncreaseDecreaseInOtherOperatingLiabilities" order="13070.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_NetCashProvidedByUsedInOperatingActivitiesContinuingOperationsAbstract" xlink:to="us-gaap_NetCashProvidedByUsedInOperatingActivitiesContinuingOperations" order="13190.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/totalLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="arwr_StatementConsolidatedStatementsOfCashFlowsLineItems" xlink:to="us-gaap_NetCashProvidedByUsedInInvestingActivitiesContinuingOperationsAbstract" order="13310.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_NetCashProvidedByUsedInInvestingActivitiesContinuingOperationsAbstract" xlink:to="us-gaap_PaymentsToAcquirePropertyPlantAndEquipment" order="13430.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2009/role/negatedLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_NetCashProvidedByUsedInInvestingActivitiesContinuingOperationsAbstract" xlink:to="us-gaap_ProceedsFromSaleMaturityAndCollectionsOfInvestments" order="13550.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_NetCashProvidedByUsedInInvestingActivitiesContinuingOperationsAbstract" xlink:to="us-gaap_ProceedsFromSaleOfPropertyPlantAndEquipment" order="13650.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_NetCashProvidedByUsedInInvestingActivitiesContinuingOperationsAbstract" xlink:to="us-gaap_PaymentsToAcquireMarketableSecurities" order="13750.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2009/role/negatedLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_NetCashProvidedByUsedInInvestingActivitiesContinuingOperationsAbstract" xlink:to="us-gaap_ProceedsFromSaleAndMaturityOfMarketableSecurities" order="13850.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_NetCashProvidedByUsedInInvestingActivitiesContinuingOperationsAbstract" xlink:to="us-gaap_CashDivestedFromDeconsolidation" order="13950.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2009/role/negatedLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_NetCashProvidedByUsedInInvestingActivitiesContinuingOperationsAbstract" xlink:to="us-gaap_PaymentsToAcquireBusinessesNetOfCashAcquired" order="14030.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2009/role/negatedLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_NetCashProvidedByUsedInInvestingActivitiesContinuingOperationsAbstract" xlink:to="us-gaap_PaymentsToAcquireAdditionalInterestInSubsidiaries" order="14110.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2009/role/negatedLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_NetCashProvidedByUsedInInvestingActivitiesContinuingOperationsAbstract" xlink:to="us-gaap_PaymentsToAcquireInterestInSubsidiariesAndAffiliates" order="14190.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2009/role/negatedLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_NetCashProvidedByUsedInInvestingActivitiesContinuingOperationsAbstract" xlink:to="us-gaap_ProceedsFromDivestitureOfInterestInSubsidiariesAndAffiliates" order="14270.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_NetCashProvidedByUsedInInvestingActivitiesContinuingOperationsAbstract" xlink:to="us-gaap_ProceedsFromDivestitureOfInterestInConsolidatedSubsidiaries" order="14350.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_NetCashProvidedByUsedInInvestingActivitiesContinuingOperationsAbstract" xlink:to="us-gaap_PaymentsToAcquireIntangibleAssets" order="14430.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2009/role/negatedLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_NetCashProvidedByUsedInInvestingActivitiesContinuingOperationsAbstract" xlink:to="us-gaap_IncreaseDecreaseInRestrictedCash" order="14510.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2009/role/negatedLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_NetCashProvidedByUsedInInvestingActivitiesContinuingOperationsAbstract" xlink:to="us-gaap_NetCashProvidedByUsedInInvestingActivitiesContinuingOperations" order="14590.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/totalLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="arwr_StatementConsolidatedStatementsOfCashFlowsLineItems" xlink:to="us-gaap_NetCashProvidedByUsedInFinancingActivitiesContinuingOperationsAbstract" order="14710.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_NetCashProvidedByUsedInFinancingActivitiesContinuingOperationsAbstract" xlink:to="us-gaap_RepaymentsOfLongTermCapitalLeaseObligations" order="14830.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2009/role/negatedLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_NetCashProvidedByUsedInFinancingActivitiesContinuingOperationsAbstract" xlink:to="us-gaap_ProceedsFromIssuanceOfCommonStock" order="14950.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_NetCashProvidedByUsedInFinancingActivitiesContinuingOperationsAbstract" xlink:to="us-gaap_ProceedsFromIssuanceOfLongTermDebt" order="15070.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_NetCashProvidedByUsedInFinancingActivitiesContinuingOperationsAbstract" xlink:to="arwr_ProceedsFromSaleOfStockInSubsidiary" order="15150.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_NetCashProvidedByUsedInFinancingActivitiesContinuingOperationsAbstract" xlink:to="us-gaap_NetCashProvidedByUsedInFinancingActivitiesContinuingOperations" order="15230.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/totalLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="arwr_StatementConsolidatedStatementsOfCashFlowsLineItems" xlink:to="us-gaap_NetCashProvidedByUsedInDiscontinuedOperationsAbstract" order="15350.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_NetCashProvidedByUsedInDiscontinuedOperationsAbstract" xlink:to="us-gaap_CashProvidedByUsedInOperatingActivitiesDiscontinuedOperations" order="15470.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_NetCashProvidedByUsedInDiscontinuedOperationsAbstract" xlink:to="us-gaap_CashProvidedByUsedInInvestingActivitiesDiscontinuedOperations" order="15570.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_NetCashProvidedByUsedInDiscontinuedOperationsAbstract" xlink:to="us-gaap_CashProvidedByUsedInFinancingActivitiesDiscontinuedOperations" order="15650.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_NetCashProvidedByUsedInDiscontinuedOperationsAbstract" xlink:to="us-gaap_NetCashProvidedByUsedInDiscontinuedOperations" order="15730.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/totalLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="arwr_StatementConsolidatedStatementsOfCashFlowsLineItems" xlink:to="us-gaap_CashAndCashEquivalentsPeriodIncreaseDecrease" order="15830.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/totalLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="arwr_StatementConsolidatedStatementsOfCashFlowsLineItems" xlink:to="us-gaap_CashAndCashEquivalentsAtCarryingValue" order="15950.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/periodStartLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="arwr_StatementConsolidatedStatementsOfCashFlowsLineItems" xlink:to="us-gaap_CashAndCashEquivalentsAtCarryingValue_li0l2" order="16030.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/periodEndLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="arwr_StatementConsolidatedStatementsOfCashFlowsLineItems" xlink:to="us-gaap_SupplementalCashFlowInformationAbstract" order="16110.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_SupplementalCashFlowInformationAbstract" xlink:to="us-gaap_InterestPaid" order="16230.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_SupplementalCashFlowInformationAbstract" xlink:to="us-gaap_IncomeTaxesPaid" order="16350.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
  </presentationLink>
  <roleRef roleURI="http://www.arrowheadresearch.com/20140331/taxonomy/role/StatementConsolidatedStatementsOfCashFlowsParenthetical" xlink:href="arwr-20140331.xsd#Role_StatementConsolidatedStatementsOfCashFlowsParenthetical" xlink:type="simple" />
  <presentationLink xlink:type="extended" xlink:role="http://www.arrowheadresearch.com/20140331/taxonomy/role/StatementConsolidatedStatementsOfCashFlowsParenthetical">
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_BusinessCombinationContingentConsiderationArrangementsChangeInAmountOfContingentConsiderationLiability1" xlink:type="locator" xlink:label="us-gaap_BusinessCombinationContingentConsiderationArrangementsChangeInAmountOfContingentConsiderationLiability1" />
    <loc xlink:href="arwr-20140331.xsd#arwr_AlvosTherapeuticsMember" xlink:type="locator" xlink:label="arwr_AlvosTherapeuticsMember" />
    <loc xlink:href="arwr-20140331.xsd#arwr_BusinessCombinationConsiderationPromissoryNoteIssued" xlink:type="locator" xlink:label="arwr_BusinessCombinationConsiderationPromissoryNoteIssued" />
    <loc xlink:href="arwr-20140331.xsd#arwr_RocheMadisonMember" xlink:type="locator" xlink:label="arwr_RocheMadisonMember" />
    <loc xlink:href="arwr-20140331.xsd#arwr_WarrantsExercised" xlink:type="locator" xlink:label="arwr_WarrantsExercised" />
    <loc xlink:href="arwr-20140331.xsd#arwr_ExercisePriceOfWarrants" xlink:type="locator" xlink:label="arwr_ExercisePriceOfWarrants" />
    <loc xlink:href="arwr-20140331.xsd#arwr_WarrantsPurchased" xlink:type="locator" xlink:label="arwr_WarrantsPurchased" />
    <loc xlink:href="arwr-20140331.xsd#arwr_WarrantsIssued" xlink:type="locator" xlink:label="arwr_WarrantsIssued" />
    <loc xlink:href="arwr-20140331.xsd#arwr_SeriesCOnePreferredStockMember" xlink:type="locator" xlink:label="arwr_SeriesCOnePreferredStockMember" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_SeriesCPreferredStockMember" xlink:type="locator" xlink:label="us-gaap_SeriesCPreferredStockMember" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_SeriesAPreferredStockMember" xlink:type="locator" xlink:label="us-gaap_SeriesAPreferredStockMember" />
    <loc xlink:href="arwr-20140331.xsd#arwr_MsEnergyLlcMember" xlink:type="locator" xlink:label="arwr_MsEnergyLlcMember" />
    <loc xlink:href="arwr-20140331.xsd#arwr_UnidymIncMember" xlink:type="locator" xlink:label="arwr_UnidymIncMember" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_SeriesEPreferredStockMember" xlink:type="locator" xlink:label="us-gaap_SeriesEPreferredStockMember" />
    <loc xlink:href="arwr-20140331.xsd#arwr_CarbonNanotechnologiesIncMember" xlink:type="locator" xlink:label="arwr_CarbonNanotechnologiesIncMember" />
    <loc xlink:href="arwr-20140331.xsd#arwr_ValueOfCommonStockPurchasedByCash" xlink:type="locator" xlink:label="arwr_ValueOfCommonStockPurchasedByCash" />
    <loc xlink:href="arwr-20140331.xsd#arwr_ValueOfCommonStockPurchasedFromMinorityShareHolders" xlink:type="locator" xlink:label="arwr_ValueOfCommonStockPurchasedFromMinorityShareHolders" />
    <loc xlink:href="arwr-20140331.xsd#arwr_CalandoPharmaceuticalsIncMember" xlink:type="locator" xlink:label="arwr_CalandoPharmaceuticalsIncMember" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_CommonStockValue" xlink:type="locator" xlink:label="us-gaap_CommonStockValue" />
    <loc xlink:href="arwr-20140331.xsd#arwr_CommonStockPurchasedFromMinorityShareHolders" xlink:type="locator" xlink:label="arwr_CommonStockPurchasedFromMinorityShareHolders" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_CommonStockSharesIssued" xlink:type="locator" xlink:label="us-gaap_CommonStockSharesIssued" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_StatementLineItems" xlink:type="locator" xlink:label="us-gaap_StatementLineItems" />
    <loc xlink:href="arwr-20140331.xsd#arwr_InsertTherapeuticsIncMember" xlink:type="locator" xlink:label="arwr_InsertTherapeuticsIncMember" />
    <loc xlink:href="arwr-20140331.xsd#arwr_IssuedToGallowayMember" xlink:type="locator" xlink:label="arwr_IssuedToGallowayMember" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ClassOfStockDomain" xlink:type="locator" xlink:label="us-gaap_ClassOfStockDomain" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_StatementClassOfStockAxis" xlink:type="locator" xlink:label="us-gaap_StatementClassOfStockAxis" />
    <loc xlink:href="http://xbrl.sec.gov/dei/2013/dei-2013-01-31.xsd#dei_EntityDomain" xlink:type="locator" xlink:label="dei_EntityDomain" />
    <loc xlink:href="http://xbrl.sec.gov/dei/2013/dei-2013-01-31.xsd#dei_LegalEntityAxis" xlink:type="locator" xlink:label="dei_LegalEntityAxis" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_StatementTable" xlink:type="locator" xlink:label="us-gaap_StatementTable" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_StatementOfCashFlowsAbstract" xlink:type="locator" xlink:label="us-gaap_StatementOfCashFlowsAbstract" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementOfCashFlowsAbstract" xlink:to="us-gaap_StatementTable" order="10010.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementTable" xlink:to="dei_LegalEntityAxis" order="10020.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="dei_LegalEntityAxis" xlink:to="dei_EntityDomain" order="10030.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementTable" xlink:to="us-gaap_StatementClassOfStockAxis" order="10020.02" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementClassOfStockAxis" xlink:to="us-gaap_ClassOfStockDomain" order="10050.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfStockDomain" xlink:to="arwr_IssuedToGallowayMember" order="10070.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="dei_EntityDomain" xlink:to="arwr_InsertTherapeuticsIncMember" order="10120.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementTable" xlink:to="us-gaap_StatementLineItems" order="10140.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_CommonStockSharesIssued" order="10180.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="arwr_CommonStockPurchasedFromMinorityShareHolders" order="10240.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_CommonStockValue" order="10360.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="dei_EntityDomain" xlink:to="arwr_CalandoPharmaceuticalsIncMember" order="10470.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="arwr_ValueOfCommonStockPurchasedFromMinorityShareHolders" order="10650.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="arwr_ValueOfCommonStockPurchasedByCash" order="10690.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="dei_EntityDomain" xlink:to="arwr_CarbonNanotechnologiesIncMember" order="10780.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfStockDomain" xlink:to="us-gaap_SeriesEPreferredStockMember" order="10830.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="dei_EntityDomain" xlink:to="arwr_UnidymIncMember" order="11020.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="dei_EntityDomain" xlink:to="arwr_MsEnergyLlcMember" order="11250.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfStockDomain" xlink:to="us-gaap_SeriesAPreferredStockMember" order="11760.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfStockDomain" xlink:to="us-gaap_SeriesCPreferredStockMember" order="12000.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfStockDomain" xlink:to="arwr_SeriesCOnePreferredStockMember" order="12900.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="arwr_WarrantsIssued" order="13510.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="arwr_WarrantsPurchased" order="13550.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="arwr_ExercisePriceOfWarrants" order="13860.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="arwr_WarrantsExercised" order="14000.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="dei_EntityDomain" xlink:to="arwr_RocheMadisonMember" order="14370.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="arwr_BusinessCombinationConsiderationPromissoryNoteIssued" order="14470.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="dei_EntityDomain" xlink:to="arwr_AlvosTherapeuticsMember" order="14560.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_BusinessCombinationContingentConsiderationArrangementsChangeInAmountOfContingentConsiderationLiability1" order="14830.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
  </presentationLink>
  <roleRef roleURI="http://www.arrowheadresearch.com/20140331/taxonomy/role/DisclosureOrganizationAndSignificantAccountingPolicies" xlink:href="arwr-20140331.xsd#Role_DisclosureOrganizationAndSignificantAccountingPolicies" xlink:type="simple" />
  <presentationLink xlink:type="extended" xlink:role="http://www.arrowheadresearch.com/20140331/taxonomy/role/DisclosureOrganizationAndSignificantAccountingPolicies">
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_OrganizationConsolidationAndPresentationOfFinancialStatementsDisclosureAndSignificantAccountingPoliciesTextBlock" xlink:type="locator" xlink:label="us-gaap_OrganizationConsolidationAndPresentationOfFinancialStatementsDisclosureAndSignificantAccountingPoliciesTextBlock" />
    <loc xlink:href="http://xbrl.sec.gov/dei/2013/dei-2013-01-31.xsd#dei_EntityDomain" xlink:type="locator" xlink:label="dei_EntityDomain" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_StatementLineItems" xlink:type="locator" xlink:label="us-gaap_StatementLineItems" />
    <loc xlink:href="http://xbrl.sec.gov/dei/2013/dei-2013-01-31.xsd#dei_LegalEntityAxis" xlink:type="locator" xlink:label="dei_LegalEntityAxis" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_StatementTable" xlink:type="locator" xlink:label="us-gaap_StatementTable" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_TextBlockAbstract" xlink:type="locator" xlink:label="us-gaap_TextBlockAbstract" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_TextBlockAbstract" xlink:to="us-gaap_StatementTable" order="10010.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementTable" xlink:to="dei_LegalEntityAxis" order="10020.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementTable" xlink:to="us-gaap_StatementLineItems" order="10030.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="dei_LegalEntityAxis" xlink:to="dei_EntityDomain" order="10040.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_OrganizationConsolidationAndPresentationOfFinancialStatementsDisclosureAndSignificantAccountingPoliciesTextBlock" order="10080.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
  </presentationLink>
  <roleRef roleURI="http://www.arrowheadresearch.com/20140331/taxonomy/role/DisclosureInvestments" xlink:href="arwr-20140331.xsd#Role_DisclosureInvestments" xlink:type="simple" />
  <presentationLink xlink:type="extended" xlink:role="http://www.arrowheadresearch.com/20140331/taxonomy/role/DisclosureInvestments">
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_CostAndEquityMethodInvestmentsDisclosureTextBlock" xlink:type="locator" xlink:label="us-gaap_CostAndEquityMethodInvestmentsDisclosureTextBlock" />
    <loc xlink:href="http://xbrl.sec.gov/dei/2013/dei-2013-01-31.xsd#dei_EntityDomain" xlink:type="locator" xlink:label="dei_EntityDomain" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_StatementLineItems" xlink:type="locator" xlink:label="us-gaap_StatementLineItems" />
    <loc xlink:href="http://xbrl.sec.gov/dei/2013/dei-2013-01-31.xsd#dei_LegalEntityAxis" xlink:type="locator" xlink:label="dei_LegalEntityAxis" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_StatementTable" xlink:type="locator" xlink:label="us-gaap_StatementTable" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_TextBlockAbstract" xlink:type="locator" xlink:label="us-gaap_TextBlockAbstract" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_TextBlockAbstract" xlink:to="us-gaap_StatementTable" order="10010.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementTable" xlink:to="dei_LegalEntityAxis" order="10020.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementTable" xlink:to="us-gaap_StatementLineItems" order="10030.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="dei_LegalEntityAxis" xlink:to="dei_EntityDomain" order="10040.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_CostAndEquityMethodInvestmentsDisclosureTextBlock" order="10080.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
  </presentationLink>
  <roleRef roleURI="http://www.arrowheadresearch.com/20140331/taxonomy/role/DisclosureFixedAssets" xlink:href="arwr-20140331.xsd#Role_DisclosureFixedAssets" xlink:type="simple" />
  <presentationLink xlink:type="extended" xlink:role="http://www.arrowheadresearch.com/20140331/taxonomy/role/DisclosureFixedAssets">
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_PropertyPlantAndEquipmentDisclosureTextBlock" xlink:type="locator" xlink:label="us-gaap_PropertyPlantAndEquipmentDisclosureTextBlock" />
    <loc xlink:href="http://xbrl.sec.gov/dei/2013/dei-2013-01-31.xsd#dei_EntityDomain" xlink:type="locator" xlink:label="dei_EntityDomain" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_StatementLineItems" xlink:type="locator" xlink:label="us-gaap_StatementLineItems" />
    <loc xlink:href="http://xbrl.sec.gov/dei/2013/dei-2013-01-31.xsd#dei_LegalEntityAxis" xlink:type="locator" xlink:label="dei_LegalEntityAxis" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_StatementTable" xlink:type="locator" xlink:label="us-gaap_StatementTable" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_TextBlockAbstract" xlink:type="locator" xlink:label="us-gaap_TextBlockAbstract" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_TextBlockAbstract" xlink:to="us-gaap_StatementTable" order="10010.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementTable" xlink:to="dei_LegalEntityAxis" order="10020.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementTable" xlink:to="us-gaap_StatementLineItems" order="10030.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="dei_LegalEntityAxis" xlink:to="dei_EntityDomain" order="10040.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_PropertyPlantAndEquipmentDisclosureTextBlock" order="10080.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
  </presentationLink>
  <roleRef roleURI="http://www.arrowheadresearch.com/20140331/taxonomy/role/DisclosureAcquisitions" xlink:href="arwr-20140331.xsd#Role_DisclosureAcquisitions" xlink:type="simple" />
  <presentationLink xlink:type="extended" xlink:role="http://www.arrowheadresearch.com/20140331/taxonomy/role/DisclosureAcquisitions">
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_BusinessCombinationDisclosureTextBlock" xlink:type="locator" xlink:label="us-gaap_BusinessCombinationDisclosureTextBlock" />
    <loc xlink:href="http://xbrl.sec.gov/dei/2013/dei-2013-01-31.xsd#dei_EntityDomain" xlink:type="locator" xlink:label="dei_EntityDomain" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_StatementLineItems" xlink:type="locator" xlink:label="us-gaap_StatementLineItems" />
    <loc xlink:href="http://xbrl.sec.gov/dei/2013/dei-2013-01-31.xsd#dei_LegalEntityAxis" xlink:type="locator" xlink:label="dei_LegalEntityAxis" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_StatementTable" xlink:type="locator" xlink:label="us-gaap_StatementTable" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_TextBlockAbstract" xlink:type="locator" xlink:label="us-gaap_TextBlockAbstract" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_TextBlockAbstract" xlink:to="us-gaap_StatementTable" order="10010.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementTable" xlink:to="dei_LegalEntityAxis" order="10020.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementTable" xlink:to="us-gaap_StatementLineItems" order="10030.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="dei_LegalEntityAxis" xlink:to="dei_EntityDomain" order="10040.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_BusinessCombinationDisclosureTextBlock" order="10080.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
  </presentationLink>
  <roleRef roleURI="http://www.arrowheadresearch.com/20140331/taxonomy/role/DisclosureIntangibleAssets" xlink:href="arwr-20140331.xsd#Role_DisclosureIntangibleAssets" xlink:type="simple" />
  <presentationLink xlink:type="extended" xlink:role="http://www.arrowheadresearch.com/20140331/taxonomy/role/DisclosureIntangibleAssets">
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_IntangibleAssetsDisclosureTextBlock" xlink:type="locator" xlink:label="us-gaap_IntangibleAssetsDisclosureTextBlock" />
    <loc xlink:href="http://xbrl.sec.gov/dei/2013/dei-2013-01-31.xsd#dei_EntityDomain" xlink:type="locator" xlink:label="dei_EntityDomain" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_StatementLineItems" xlink:type="locator" xlink:label="us-gaap_StatementLineItems" />
    <loc xlink:href="http://xbrl.sec.gov/dei/2013/dei-2013-01-31.xsd#dei_LegalEntityAxis" xlink:type="locator" xlink:label="dei_LegalEntityAxis" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_StatementTable" xlink:type="locator" xlink:label="us-gaap_StatementTable" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_TextBlockAbstract" xlink:type="locator" xlink:label="us-gaap_TextBlockAbstract" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_TextBlockAbstract" xlink:to="us-gaap_StatementTable" order="10010.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementTable" xlink:to="dei_LegalEntityAxis" order="10020.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementTable" xlink:to="us-gaap_StatementLineItems" order="10030.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="dei_LegalEntityAxis" xlink:to="dei_EntityDomain" order="10040.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_IntangibleAssetsDisclosureTextBlock" order="10080.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
  </presentationLink>
  <roleRef roleURI="http://www.arrowheadresearch.com/20140331/taxonomy/role/DisclosureInvestmentInSubsidiaries" xlink:href="arwr-20140331.xsd#Role_DisclosureInvestmentInSubsidiaries" xlink:type="simple" />
  <presentationLink xlink:type="extended" xlink:role="http://www.arrowheadresearch.com/20140331/taxonomy/role/DisclosureInvestmentInSubsidiaries">
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_EquityMethodInvestmentsDisclosureTextBlock" xlink:type="locator" xlink:label="us-gaap_EquityMethodInvestmentsDisclosureTextBlock" />
    <loc xlink:href="http://xbrl.sec.gov/dei/2013/dei-2013-01-31.xsd#dei_EntityDomain" xlink:type="locator" xlink:label="dei_EntityDomain" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_StatementLineItems" xlink:type="locator" xlink:label="us-gaap_StatementLineItems" />
    <loc xlink:href="http://xbrl.sec.gov/dei/2013/dei-2013-01-31.xsd#dei_LegalEntityAxis" xlink:type="locator" xlink:label="dei_LegalEntityAxis" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_StatementTable" xlink:type="locator" xlink:label="us-gaap_StatementTable" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_TextBlockAbstract" xlink:type="locator" xlink:label="us-gaap_TextBlockAbstract" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_TextBlockAbstract" xlink:to="us-gaap_StatementTable" order="10010.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementTable" xlink:to="dei_LegalEntityAxis" order="10020.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementTable" xlink:to="us-gaap_StatementLineItems" order="10030.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="dei_LegalEntityAxis" xlink:to="dei_EntityDomain" order="10040.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_EquityMethodInvestmentsDisclosureTextBlock" order="10080.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
  </presentationLink>
  <roleRef roleURI="http://www.arrowheadresearch.com/20140331/taxonomy/role/DisclosureNotesPayable" xlink:href="arwr-20140331.xsd#Role_DisclosureNotesPayable" xlink:type="simple" />
  <presentationLink xlink:type="extended" xlink:role="http://www.arrowheadresearch.com/20140331/taxonomy/role/DisclosureNotesPayable">
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DebtDisclosureTextBlock" xlink:type="locator" xlink:label="us-gaap_DebtDisclosureTextBlock" />
    <loc xlink:href="http://xbrl.sec.gov/dei/2013/dei-2013-01-31.xsd#dei_EntityDomain" xlink:type="locator" xlink:label="dei_EntityDomain" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_StatementLineItems" xlink:type="locator" xlink:label="us-gaap_StatementLineItems" />
    <loc xlink:href="http://xbrl.sec.gov/dei/2013/dei-2013-01-31.xsd#dei_LegalEntityAxis" xlink:type="locator" xlink:label="dei_LegalEntityAxis" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_StatementTable" xlink:type="locator" xlink:label="us-gaap_StatementTable" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_TextBlockAbstract" xlink:type="locator" xlink:label="us-gaap_TextBlockAbstract" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_TextBlockAbstract" xlink:to="us-gaap_StatementTable" order="10010.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementTable" xlink:to="dei_LegalEntityAxis" order="10020.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementTable" xlink:to="us-gaap_StatementLineItems" order="10030.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="dei_LegalEntityAxis" xlink:to="dei_EntityDomain" order="10040.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_DebtDisclosureTextBlock" order="10080.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
  </presentationLink>
  <roleRef roleURI="http://www.arrowheadresearch.com/20140331/taxonomy/role/DisclosureStockholdersEquity" xlink:href="arwr-20140331.xsd#Role_DisclosureStockholdersEquity" xlink:type="simple" />
  <presentationLink xlink:type="extended" xlink:role="http://www.arrowheadresearch.com/20140331/taxonomy/role/DisclosureStockholdersEquity">
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_StockholdersEquityNoteDisclosureTextBlock" xlink:type="locator" xlink:label="us-gaap_StockholdersEquityNoteDisclosureTextBlock" />
    <loc xlink:href="http://xbrl.sec.gov/dei/2013/dei-2013-01-31.xsd#dei_EntityDomain" xlink:type="locator" xlink:label="dei_EntityDomain" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_StatementLineItems" xlink:type="locator" xlink:label="us-gaap_StatementLineItems" />
    <loc xlink:href="http://xbrl.sec.gov/dei/2013/dei-2013-01-31.xsd#dei_LegalEntityAxis" xlink:type="locator" xlink:label="dei_LegalEntityAxis" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_StatementTable" xlink:type="locator" xlink:label="us-gaap_StatementTable" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_TextBlockAbstract" xlink:type="locator" xlink:label="us-gaap_TextBlockAbstract" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_TextBlockAbstract" xlink:to="us-gaap_StatementTable" order="10010.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementTable" xlink:to="dei_LegalEntityAxis" order="10020.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementTable" xlink:to="us-gaap_StatementLineItems" order="10030.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="dei_LegalEntityAxis" xlink:to="dei_EntityDomain" order="10040.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_StockholdersEquityNoteDisclosureTextBlock" order="10080.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
  </presentationLink>
  <roleRef roleURI="http://www.arrowheadresearch.com/20140331/taxonomy/role/DisclosureLeases" xlink:href="arwr-20140331.xsd#Role_DisclosureLeases" xlink:type="simple" />
  <presentationLink xlink:type="extended" xlink:role="http://www.arrowheadresearch.com/20140331/taxonomy/role/DisclosureLeases">
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_LeasesOfLesseeDisclosureTextBlock" xlink:type="locator" xlink:label="us-gaap_LeasesOfLesseeDisclosureTextBlock" />
    <loc xlink:href="http://xbrl.sec.gov/dei/2013/dei-2013-01-31.xsd#dei_EntityDomain" xlink:type="locator" xlink:label="dei_EntityDomain" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_StatementLineItems" xlink:type="locator" xlink:label="us-gaap_StatementLineItems" />
    <loc xlink:href="http://xbrl.sec.gov/dei/2013/dei-2013-01-31.xsd#dei_LegalEntityAxis" xlink:type="locator" xlink:label="dei_LegalEntityAxis" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_StatementTable" xlink:type="locator" xlink:label="us-gaap_StatementTable" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_TextBlockAbstract" xlink:type="locator" xlink:label="us-gaap_TextBlockAbstract" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_TextBlockAbstract" xlink:to="us-gaap_StatementTable" order="10010.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementTable" xlink:to="dei_LegalEntityAxis" order="10020.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementTable" xlink:to="us-gaap_StatementLineItems" order="10030.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="dei_LegalEntityAxis" xlink:to="dei_EntityDomain" order="10040.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_LeasesOfLesseeDisclosureTextBlock" order="10080.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
  </presentationLink>
  <roleRef roleURI="http://www.arrowheadresearch.com/20140331/taxonomy/role/DisclosureStockBasedCompensation" xlink:href="arwr-20140331.xsd#Role_DisclosureStockBasedCompensation" xlink:type="simple" />
  <presentationLink xlink:type="extended" xlink:role="http://www.arrowheadresearch.com/20140331/taxonomy/role/DisclosureStockBasedCompensation">
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DisclosureOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTextBlock" xlink:type="locator" xlink:label="us-gaap_DisclosureOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTextBlock" />
    <loc xlink:href="http://xbrl.sec.gov/dei/2013/dei-2013-01-31.xsd#dei_EntityDomain" xlink:type="locator" xlink:label="dei_EntityDomain" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_StatementLineItems" xlink:type="locator" xlink:label="us-gaap_StatementLineItems" />
    <loc xlink:href="http://xbrl.sec.gov/dei/2013/dei-2013-01-31.xsd#dei_LegalEntityAxis" xlink:type="locator" xlink:label="dei_LegalEntityAxis" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_StatementTable" xlink:type="locator" xlink:label="us-gaap_StatementTable" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_TextBlockAbstract" xlink:type="locator" xlink:label="us-gaap_TextBlockAbstract" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_TextBlockAbstract" xlink:to="us-gaap_StatementTable" order="10010.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementTable" xlink:to="dei_LegalEntityAxis" order="10020.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementTable" xlink:to="us-gaap_StatementLineItems" order="10030.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="dei_LegalEntityAxis" xlink:to="dei_EntityDomain" order="10040.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_DisclosureOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTextBlock" order="10080.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
  </presentationLink>
  <roleRef roleURI="http://www.arrowheadresearch.com/20140331/taxonomy/role/DisclosureFairValueMeasurements" xlink:href="arwr-20140331.xsd#Role_DisclosureFairValueMeasurements" xlink:type="simple" />
  <presentationLink xlink:type="extended" xlink:role="http://www.arrowheadresearch.com/20140331/taxonomy/role/DisclosureFairValueMeasurements">
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_FairValueDisclosuresTextBlock" xlink:type="locator" xlink:label="us-gaap_FairValueDisclosuresTextBlock" />
    <loc xlink:href="http://xbrl.sec.gov/dei/2013/dei-2013-01-31.xsd#dei_EntityDomain" xlink:type="locator" xlink:label="dei_EntityDomain" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_StatementLineItems" xlink:type="locator" xlink:label="us-gaap_StatementLineItems" />
    <loc xlink:href="http://xbrl.sec.gov/dei/2013/dei-2013-01-31.xsd#dei_LegalEntityAxis" xlink:type="locator" xlink:label="dei_LegalEntityAxis" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_StatementTable" xlink:type="locator" xlink:label="us-gaap_StatementTable" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_TextBlockAbstract" xlink:type="locator" xlink:label="us-gaap_TextBlockAbstract" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_TextBlockAbstract" xlink:to="us-gaap_StatementTable" order="10010.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementTable" xlink:to="dei_LegalEntityAxis" order="10020.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementTable" xlink:to="us-gaap_StatementLineItems" order="10030.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="dei_LegalEntityAxis" xlink:to="dei_EntityDomain" order="10040.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_FairValueDisclosuresTextBlock" order="10080.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
  </presentationLink>
  <roleRef roleURI="http://www.arrowheadresearch.com/20140331/taxonomy/role/DisclosureOrganizationAndSignificantAccountingPoliciesPolicies" xlink:href="arwr-20140331.xsd#Role_DisclosureOrganizationAndSignificantAccountingPoliciesPolicies" xlink:type="simple" />
  <presentationLink xlink:type="extended" xlink:role="http://www.arrowheadresearch.com/20140331/taxonomy/role/DisclosureOrganizationAndSignificantAccountingPoliciesPolicies">
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_NewAccountingPronouncementsPolicyPolicyTextBlock" xlink:type="locator" xlink:label="us-gaap_NewAccountingPronouncementsPolicyPolicyTextBlock" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_IncomeTaxPolicyTextBlock" xlink:type="locator" xlink:label="us-gaap_IncomeTaxPolicyTextBlock" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DerivativesPolicyTextBlock" xlink:type="locator" xlink:label="us-gaap_DerivativesPolicyTextBlock" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ShareBasedCompensationOptionAndIncentivePlansPolicy" xlink:type="locator" xlink:label="us-gaap_ShareBasedCompensationOptionAndIncentivePlansPolicy" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_EarningsPerSharePolicyTextBlock" xlink:type="locator" xlink:label="us-gaap_EarningsPerSharePolicyTextBlock" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ResearchAndDevelopmentExpensePolicy" xlink:type="locator" xlink:label="us-gaap_ResearchAndDevelopmentExpensePolicy" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_TradeAndOtherAccountsReceivablePolicy" xlink:type="locator" xlink:label="us-gaap_TradeAndOtherAccountsReceivablePolicy" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_RevenueRecognitionPolicyTextBlock" xlink:type="locator" xlink:label="us-gaap_RevenueRecognitionPolicyTextBlock" />
    <loc xlink:href="arwr-20140331.xsd#arwr_NoncontrollingInterestsPolicyTextBlock" xlink:type="locator" xlink:label="arwr_NoncontrollingInterestsPolicyTextBlock" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_EquityAndCostMethodInvestmentsPolicy" xlink:type="locator" xlink:label="us-gaap_EquityAndCostMethodInvestmentsPolicy" />
    <loc xlink:href="arwr-20140331.xsd#arwr_ContingentConsiderationPolicyTextBlock" xlink:type="locator" xlink:label="arwr_ContingentConsiderationPolicyTextBlock" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_InProcessResearchAndDevelopmentPolicy" xlink:type="locator" xlink:label="us-gaap_InProcessResearchAndDevelopmentPolicy" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_GoodwillAndIntangibleAssetsPolicyTextBlock" xlink:type="locator" xlink:label="us-gaap_GoodwillAndIntangibleAssetsPolicyTextBlock" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_PropertyPlantAndEquipmentPolicyTextBlock" xlink:type="locator" xlink:label="us-gaap_PropertyPlantAndEquipmentPolicyTextBlock" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_InvestmentPolicyTextBlock" xlink:type="locator" xlink:label="us-gaap_InvestmentPolicyTextBlock" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ConcentrationRiskCreditRisk" xlink:type="locator" xlink:label="us-gaap_ConcentrationRiskCreditRisk" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_CashAndCashEquivalentsRestrictedCashAndCashEquivalentsPolicy" xlink:type="locator" xlink:label="us-gaap_CashAndCashEquivalentsRestrictedCashAndCashEquivalentsPolicy" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_UseOfEstimates" xlink:type="locator" xlink:label="us-gaap_UseOfEstimates" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_BasisOfPresentationAndSignificantAccountingPoliciesTextBlock" xlink:type="locator" xlink:label="us-gaap_BasisOfPresentationAndSignificantAccountingPoliciesTextBlock" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ConsolidationPolicyTextBlock" xlink:type="locator" xlink:label="us-gaap_ConsolidationPolicyTextBlock" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_LiquidityDisclosureTextBlock" xlink:type="locator" xlink:label="us-gaap_LiquidityDisclosureTextBlock" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_BusinessDescriptionAndAccountingPoliciesTextBlock" xlink:type="locator" xlink:label="us-gaap_BusinessDescriptionAndAccountingPoliciesTextBlock" />
    <loc xlink:href="http://xbrl.sec.gov/dei/2013/dei-2013-01-31.xsd#dei_EntityDomain" xlink:type="locator" xlink:label="dei_EntityDomain" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_StatementLineItems" xlink:type="locator" xlink:label="us-gaap_StatementLineItems" />
    <loc xlink:href="http://xbrl.sec.gov/dei/2013/dei-2013-01-31.xsd#dei_LegalEntityAxis" xlink:type="locator" xlink:label="dei_LegalEntityAxis" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_StatementTable" xlink:type="locator" xlink:label="us-gaap_StatementTable" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_TextBlockAbstract" xlink:type="locator" xlink:label="us-gaap_TextBlockAbstract" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_TextBlockAbstract" xlink:to="us-gaap_StatementTable" order="10010.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementTable" xlink:to="dei_LegalEntityAxis" order="10020.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementTable" xlink:to="us-gaap_StatementLineItems" order="10030.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="dei_LegalEntityAxis" xlink:to="dei_EntityDomain" order="10040.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_BusinessDescriptionAndAccountingPoliciesTextBlock" order="10080.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_LiquidityDisclosureTextBlock" order="10160.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_ConsolidationPolicyTextBlock" order="10240.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_BasisOfPresentationAndSignificantAccountingPoliciesTextBlock" order="10320.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_UseOfEstimates" order="10400.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_CashAndCashEquivalentsRestrictedCashAndCashEquivalentsPolicy" order="10480.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_ConcentrationRiskCreditRisk" order="10560.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_InvestmentPolicyTextBlock" order="10640.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_PropertyPlantAndEquipmentPolicyTextBlock" order="10720.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_GoodwillAndIntangibleAssetsPolicyTextBlock" order="10800.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_InProcessResearchAndDevelopmentPolicy" order="10880.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="arwr_ContingentConsiderationPolicyTextBlock" order="10960.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_EquityAndCostMethodInvestmentsPolicy" order="11040.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="arwr_NoncontrollingInterestsPolicyTextBlock" order="11120.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_RevenueRecognitionPolicyTextBlock" order="11200.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_TradeAndOtherAccountsReceivablePolicy" order="11280.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_ResearchAndDevelopmentExpensePolicy" order="11360.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_EarningsPerSharePolicyTextBlock" order="11440.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_ShareBasedCompensationOptionAndIncentivePlansPolicy" order="11520.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_DerivativesPolicyTextBlock" order="11600.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_IncomeTaxPolicyTextBlock" order="11680.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_NewAccountingPronouncementsPolicyPolicyTextBlock" order="11760.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
  </presentationLink>
  <roleRef roleURI="http://www.arrowheadresearch.com/20140331/taxonomy/role/DisclosureInvestmentsTables" xlink:href="arwr-20140331.xsd#Role_DisclosureInvestmentsTables" xlink:type="simple" />
  <presentationLink xlink:type="extended" xlink:role="http://www.arrowheadresearch.com/20140331/taxonomy/role/DisclosureInvestmentsTables">
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_HeldToMaturitySecuritiesTextBlock" xlink:type="locator" xlink:label="us-gaap_HeldToMaturitySecuritiesTextBlock" />
    <loc xlink:href="http://xbrl.sec.gov/dei/2013/dei-2013-01-31.xsd#dei_EntityDomain" xlink:type="locator" xlink:label="dei_EntityDomain" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_StatementLineItems" xlink:type="locator" xlink:label="us-gaap_StatementLineItems" />
    <loc xlink:href="http://xbrl.sec.gov/dei/2013/dei-2013-01-31.xsd#dei_LegalEntityAxis" xlink:type="locator" xlink:label="dei_LegalEntityAxis" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_StatementTable" xlink:type="locator" xlink:label="us-gaap_StatementTable" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_TextBlockAbstract" xlink:type="locator" xlink:label="us-gaap_TextBlockAbstract" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_TextBlockAbstract" xlink:to="us-gaap_StatementTable" order="10010.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementTable" xlink:to="dei_LegalEntityAxis" order="10020.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementTable" xlink:to="us-gaap_StatementLineItems" order="10030.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="dei_LegalEntityAxis" xlink:to="dei_EntityDomain" order="10040.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_HeldToMaturitySecuritiesTextBlock" order="10080.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
  </presentationLink>
  <roleRef roleURI="http://www.arrowheadresearch.com/20140331/taxonomy/role/DisclosureFixedAssetsTables" xlink:href="arwr-20140331.xsd#Role_DisclosureFixedAssetsTables" xlink:type="simple" />
  <presentationLink xlink:type="extended" xlink:role="http://www.arrowheadresearch.com/20140331/taxonomy/role/DisclosureFixedAssetsTables">
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_PropertyPlantAndEquipmentTextBlock" xlink:type="locator" xlink:label="us-gaap_PropertyPlantAndEquipmentTextBlock" />
    <loc xlink:href="http://xbrl.sec.gov/dei/2013/dei-2013-01-31.xsd#dei_EntityDomain" xlink:type="locator" xlink:label="dei_EntityDomain" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_StatementLineItems" xlink:type="locator" xlink:label="us-gaap_StatementLineItems" />
    <loc xlink:href="http://xbrl.sec.gov/dei/2013/dei-2013-01-31.xsd#dei_LegalEntityAxis" xlink:type="locator" xlink:label="dei_LegalEntityAxis" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_StatementTable" xlink:type="locator" xlink:label="us-gaap_StatementTable" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_TextBlockAbstract" xlink:type="locator" xlink:label="us-gaap_TextBlockAbstract" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_TextBlockAbstract" xlink:to="us-gaap_StatementTable" order="10010.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementTable" xlink:to="dei_LegalEntityAxis" order="10020.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementTable" xlink:to="us-gaap_StatementLineItems" order="10030.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="dei_LegalEntityAxis" xlink:to="dei_EntityDomain" order="10040.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_PropertyPlantAndEquipmentTextBlock" order="10080.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
  </presentationLink>
  <roleRef roleURI="http://www.arrowheadresearch.com/20140331/taxonomy/role/DisclosureIntangibleAssetsTables" xlink:href="arwr-20140331.xsd#Role_DisclosureIntangibleAssetsTables" xlink:type="simple" />
  <presentationLink xlink:type="extended" xlink:role="http://www.arrowheadresearch.com/20140331/taxonomy/role/DisclosureIntangibleAssetsTables">
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ScheduleOfIntangibleAssetsAndGoodwillTableTextBlock" xlink:type="locator" xlink:label="us-gaap_ScheduleOfIntangibleAssetsAndGoodwillTableTextBlock" />
    <loc xlink:href="http://xbrl.sec.gov/dei/2013/dei-2013-01-31.xsd#dei_EntityDomain" xlink:type="locator" xlink:label="dei_EntityDomain" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_StatementLineItems" xlink:type="locator" xlink:label="us-gaap_StatementLineItems" />
    <loc xlink:href="http://xbrl.sec.gov/dei/2013/dei-2013-01-31.xsd#dei_LegalEntityAxis" xlink:type="locator" xlink:label="dei_LegalEntityAxis" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_StatementTable" xlink:type="locator" xlink:label="us-gaap_StatementTable" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_TextBlockAbstract" xlink:type="locator" xlink:label="us-gaap_TextBlockAbstract" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_TextBlockAbstract" xlink:to="us-gaap_StatementTable" order="10010.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementTable" xlink:to="dei_LegalEntityAxis" order="10020.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementTable" xlink:to="us-gaap_StatementLineItems" order="10030.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="dei_LegalEntityAxis" xlink:to="dei_EntityDomain" order="10040.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_ScheduleOfIntangibleAssetsAndGoodwillTableTextBlock" order="10080.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
  </presentationLink>
  <roleRef roleURI="http://www.arrowheadresearch.com/20140331/taxonomy/role/DisclosureStockholdersEquityTables" xlink:href="arwr-20140331.xsd#Role_DisclosureStockholdersEquityTables" xlink:type="simple" />
  <presentationLink xlink:type="extended" xlink:role="http://www.arrowheadresearch.com/20140331/taxonomy/role/DisclosureStockholdersEquityTables">
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ScheduleOfStockholdersEquityNoteWarrantsOrRightsTextBlock" xlink:type="locator" xlink:label="us-gaap_ScheduleOfStockholdersEquityNoteWarrantsOrRightsTextBlock" />
    <loc xlink:href="http://xbrl.sec.gov/dei/2013/dei-2013-01-31.xsd#dei_EntityDomain" xlink:type="locator" xlink:label="dei_EntityDomain" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_StatementLineItems" xlink:type="locator" xlink:label="us-gaap_StatementLineItems" />
    <loc xlink:href="http://xbrl.sec.gov/dei/2013/dei-2013-01-31.xsd#dei_LegalEntityAxis" xlink:type="locator" xlink:label="dei_LegalEntityAxis" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_StatementTable" xlink:type="locator" xlink:label="us-gaap_StatementTable" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_TextBlockAbstract" xlink:type="locator" xlink:label="us-gaap_TextBlockAbstract" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_TextBlockAbstract" xlink:to="us-gaap_StatementTable" order="10010.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementTable" xlink:to="dei_LegalEntityAxis" order="10020.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementTable" xlink:to="us-gaap_StatementLineItems" order="10030.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="dei_LegalEntityAxis" xlink:to="dei_EntityDomain" order="10040.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_ScheduleOfStockholdersEquityNoteWarrantsOrRightsTextBlock" order="10080.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
  </presentationLink>
  <roleRef roleURI="http://www.arrowheadresearch.com/20140331/taxonomy/role/DisclosureLeasesTables" xlink:href="arwr-20140331.xsd#Role_DisclosureLeasesTables" xlink:type="simple" />
  <presentationLink xlink:type="extended" xlink:role="http://www.arrowheadresearch.com/20140331/taxonomy/role/DisclosureLeasesTables">
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ScheduleOfFutureMinimumRentalPaymentsForOperatingLeasesTableTextBlock" xlink:type="locator" xlink:label="us-gaap_ScheduleOfFutureMinimumRentalPaymentsForOperatingLeasesTableTextBlock" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ScheduleOfFutureMinimumLeasePaymentsForCapitalLeasesTableTextBlock" xlink:type="locator" xlink:label="us-gaap_ScheduleOfFutureMinimumLeasePaymentsForCapitalLeasesTableTextBlock" />
    <loc xlink:href="http://xbrl.sec.gov/dei/2013/dei-2013-01-31.xsd#dei_EntityDomain" xlink:type="locator" xlink:label="dei_EntityDomain" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_StatementLineItems" xlink:type="locator" xlink:label="us-gaap_StatementLineItems" />
    <loc xlink:href="http://xbrl.sec.gov/dei/2013/dei-2013-01-31.xsd#dei_LegalEntityAxis" xlink:type="locator" xlink:label="dei_LegalEntityAxis" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_StatementTable" xlink:type="locator" xlink:label="us-gaap_StatementTable" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_TextBlockAbstract" xlink:type="locator" xlink:label="us-gaap_TextBlockAbstract" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_TextBlockAbstract" xlink:to="us-gaap_StatementTable" order="10010.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementTable" xlink:to="dei_LegalEntityAxis" order="10020.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementTable" xlink:to="us-gaap_StatementLineItems" order="10030.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="dei_LegalEntityAxis" xlink:to="dei_EntityDomain" order="10040.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_ScheduleOfFutureMinimumLeasePaymentsForCapitalLeasesTableTextBlock" order="10080.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_ScheduleOfFutureMinimumRentalPaymentsForOperatingLeasesTableTextBlock" order="10160.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
  </presentationLink>
  <roleRef roleURI="http://www.arrowheadresearch.com/20140331/taxonomy/role/DisclosureStockBasedCompensationTables" xlink:href="arwr-20140331.xsd#Role_DisclosureStockBasedCompensationTables" xlink:type="simple" />
  <presentationLink xlink:type="extended" xlink:role="http://www.arrowheadresearch.com/20140331/taxonomy/role/DisclosureStockBasedCompensationTables">
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ScheduleOfShareBasedCompensationRestrictedStockUnitsAwardActivityTableTextBlock" xlink:type="locator" xlink:label="us-gaap_ScheduleOfShareBasedCompensationRestrictedStockUnitsAwardActivityTableTextBlock" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ScheduleOfShareBasedPaymentAwardEmployeeStockPurchasePlanValuationAssumptionsTableTextBlock" xlink:type="locator" xlink:label="us-gaap_ScheduleOfShareBasedPaymentAwardEmployeeStockPurchasePlanValuationAssumptionsTableTextBlock" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ScheduleOfShareBasedCompensationStockOptionsActivityTableTextBlock" xlink:type="locator" xlink:label="us-gaap_ScheduleOfShareBasedCompensationStockOptionsActivityTableTextBlock" />
    <loc xlink:href="http://xbrl.sec.gov/dei/2013/dei-2013-01-31.xsd#dei_EntityDomain" xlink:type="locator" xlink:label="dei_EntityDomain" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_StatementLineItems" xlink:type="locator" xlink:label="us-gaap_StatementLineItems" />
    <loc xlink:href="http://xbrl.sec.gov/dei/2013/dei-2013-01-31.xsd#dei_LegalEntityAxis" xlink:type="locator" xlink:label="dei_LegalEntityAxis" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_StatementTable" xlink:type="locator" xlink:label="us-gaap_StatementTable" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_TextBlockAbstract" xlink:type="locator" xlink:label="us-gaap_TextBlockAbstract" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_TextBlockAbstract" xlink:to="us-gaap_StatementTable" order="10010.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementTable" xlink:to="dei_LegalEntityAxis" order="10020.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementTable" xlink:to="us-gaap_StatementLineItems" order="10030.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="dei_LegalEntityAxis" xlink:to="dei_EntityDomain" order="10040.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_ScheduleOfShareBasedCompensationStockOptionsActivityTableTextBlock" order="10080.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_ScheduleOfShareBasedPaymentAwardEmployeeStockPurchasePlanValuationAssumptionsTableTextBlock" order="10160.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_ScheduleOfShareBasedCompensationRestrictedStockUnitsAwardActivityTableTextBlock" order="10240.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
  </presentationLink>
  <roleRef roleURI="http://www.arrowheadresearch.com/20140331/taxonomy/role/DisclosureFairValueMeasurementsTables" xlink:href="arwr-20140331.xsd#Role_DisclosureFairValueMeasurementsTables" xlink:type="simple" />
  <presentationLink xlink:type="extended" xlink:role="http://www.arrowheadresearch.com/20140331/taxonomy/role/DisclosureFairValueMeasurementsTables">
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionContingentConsiderationTextBlock" xlink:type="locator" xlink:label="us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionContingentConsiderationTextBlock" />
    <loc xlink:href="arwr-20140331.xsd#arwr_ExchangeRightsMember" xlink:type="locator" xlink:label="arwr_ExchangeRightsMember" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationTextBlock" xlink:type="locator" xlink:label="us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationTextBlock" />
    <loc xlink:href="arwr-20140331.xsd#arwr_FairValueAssumptionsAndMethodologyForLiabilitiesTableTextBlock" xlink:type="locator" xlink:label="arwr_FairValueAssumptionsAndMethodologyForLiabilitiesTableTextBlock" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_WarrantMember" xlink:type="locator" xlink:label="us-gaap_WarrantMember" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationByLiabilityClassDomain" xlink:type="locator" xlink:label="us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationByLiabilityClassDomain" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_FairValueByLiabilityClassAxis" xlink:type="locator" xlink:label="us-gaap_FairValueByLiabilityClassAxis" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationTextBlock" xlink:type="locator" xlink:label="us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationTextBlock" />
    <loc xlink:href="arwr-20140331.xsd#arwr_FairValueAssumptionsAndMethodologyForAssetsTableTextBlock" xlink:type="locator" xlink:label="arwr_FairValueAssumptionsAndMethodologyForAssetsTableTextBlock" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ScheduleOfFairValueAssetsAndLiabilitiesMeasuredOnRecurringBasisTableTextBlock" xlink:type="locator" xlink:label="us-gaap_ScheduleOfFairValueAssetsAndLiabilitiesMeasuredOnRecurringBasisTableTextBlock" />
    <loc xlink:href="http://xbrl.sec.gov/dei/2013/dei-2013-01-31.xsd#dei_EntityDomain" xlink:type="locator" xlink:label="dei_EntityDomain" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_StatementLineItems" xlink:type="locator" xlink:label="us-gaap_StatementLineItems" />
    <loc xlink:href="http://xbrl.sec.gov/dei/2013/dei-2013-01-31.xsd#dei_LegalEntityAxis" xlink:type="locator" xlink:label="dei_LegalEntityAxis" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_StatementTable" xlink:type="locator" xlink:label="us-gaap_StatementTable" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_TextBlockAbstract" xlink:type="locator" xlink:label="us-gaap_TextBlockAbstract" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_TextBlockAbstract" xlink:to="us-gaap_StatementTable" order="10010.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementTable" xlink:to="dei_LegalEntityAxis" order="10020.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementTable" xlink:to="us-gaap_StatementLineItems" order="10030.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="dei_LegalEntityAxis" xlink:to="dei_EntityDomain" order="10040.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_ScheduleOfFairValueAssetsAndLiabilitiesMeasuredOnRecurringBasisTableTextBlock" order="10080.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="arwr_FairValueAssumptionsAndMethodologyForAssetsTableTextBlock" order="10160.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationTextBlock" order="10240.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementTable" xlink:to="us-gaap_FairValueByLiabilityClassAxis" order="10020.02" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueByLiabilityClassAxis" xlink:to="us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationByLiabilityClassDomain" order="10280.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationByLiabilityClassDomain" xlink:to="us-gaap_WarrantMember" order="10300.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="arwr_FairValueAssumptionsAndMethodologyForLiabilitiesTableTextBlock" order="10370.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationTextBlock" order="10450.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationByLiabilityClassDomain" xlink:to="arwr_ExchangeRightsMember" order="10510.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementLineItems" xlink:to="us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionContingentConsiderationTextBlock" order="10790.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
  </presentationLink>
  <roleRef roleURI="http://www.arrowheadresearch.com/20140331/taxonomy/role/DisclosureOrganizationAndSignificantAccountingPoliciesAdditionalInformationDetail" xlink:href="arwr-20140331.xsd#Role_DisclosureOrganizationAndSignificantAccountingPoliciesAdditionalInformationDetail" xlink:type="simple" />
  <presentationLink xlink:type="extended" xlink:role="http://www.arrowheadresearch.com/20140331/taxonomy/role/DisclosureOrganizationAndSignificantAccountingPoliciesAdditionalInformationDetail">
    <loc xlink:href="arwr-20140331.xsd#arwr_CostMethodInvestmentAttributableToNoncontrollingInterest" xlink:type="locator" xlink:label="arwr_CostMethodInvestmentAttributableToNoncontrollingInterest" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_PropertyPlantAndEquipmentUsefulLife" xlink:type="locator" xlink:label="us-gaap_PropertyPlantAndEquipmentUsefulLife" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_MaximumMember" xlink:type="locator" xlink:label="us-gaap_MaximumMember" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_MinimumMember" xlink:type="locator" xlink:label="us-gaap_MinimumMember" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_RangeMember" xlink:type="locator" xlink:label="us-gaap_RangeMember" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_RangeAxis" xlink:type="locator" xlink:label="us-gaap_RangeAxis" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_InvestmentsFairValueDisclosure" xlink:type="locator" xlink:label="us-gaap_InvestmentsFairValueDisclosure" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_UnrealizedGainOnSecurities" xlink:type="locator" xlink:label="us-gaap_UnrealizedGainOnSecurities" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_UnrealizedLossOnSecurities" xlink:type="locator" xlink:label="us-gaap_UnrealizedLossOnSecurities" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_MarketableSecurities" xlink:type="locator" xlink:label="us-gaap_MarketableSecurities" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_CashFDICInsuredAmount" xlink:type="locator" xlink:label="us-gaap_CashFDICInsuredAmount" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_RestrictedCashAndCashEquivalents" xlink:type="locator" xlink:label="us-gaap_RestrictedCashAndCashEquivalents" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_PaymentsToAcquireOtherPropertyPlantAndEquipment" xlink:type="locator" xlink:label="us-gaap_PaymentsToAcquireOtherPropertyPlantAndEquipment" />
    <loc xlink:href="arwr-20140331.xsd#arwr_OperatingCashOutflow" xlink:type="locator" xlink:label="arwr_OperatingCashOutflow" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_PaymentsToAcquireProjects" xlink:type="locator" xlink:label="us-gaap_PaymentsToAcquireProjects" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ProceedsFromIssuanceOfWarrants" xlink:type="locator" xlink:label="us-gaap_ProceedsFromIssuanceOfWarrants" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ProceedsFromIssuanceOrSaleOfEquity" xlink:type="locator" xlink:label="us-gaap_ProceedsFromIssuanceOrSaleOfEquity" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_CashAndCashEquivalentsPeriodIncreaseDecrease" xlink:type="locator" xlink:label="us-gaap_CashAndCashEquivalentsPeriodIncreaseDecrease" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_Investments" xlink:type="locator" xlink:label="us-gaap_Investments" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DebtInstrumentMaturityDateDescription" xlink:type="locator" xlink:label="us-gaap_DebtInstrumentMaturityDateDescription" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_CashAndCashEquivalentsAtCarryingValue" xlink:type="locator" xlink:label="us-gaap_CashAndCashEquivalentsAtCarryingValue" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ScheduleOfInvestmentsLineItems" xlink:type="locator" xlink:label="us-gaap_ScheduleOfInvestmentsLineItems" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_BondsMember" xlink:type="locator" xlink:label="us-gaap_BondsMember" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_SummaryOfInvestmentsByTypeDomain" xlink:type="locator" xlink:label="us-gaap_SummaryOfInvestmentsByTypeDomain" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_SummaryOfInvestmentsOtherThanInvestmentsInRelatedPartiesByTypeAxis" xlink:type="locator" xlink:label="us-gaap_SummaryOfInvestmentsOtherThanInvestmentsInRelatedPartiesByTypeAxis" />
    <loc xlink:href="arwr-20140331.xsd#arwr_WarrantsIssuedMember" xlink:type="locator" xlink:label="arwr_WarrantsIssuedMember" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ScenarioUnspecifiedDomain" xlink:type="locator" xlink:label="us-gaap_ScenarioUnspecifiedDomain" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_StatementScenarioAxis" xlink:type="locator" xlink:label="us-gaap_StatementScenarioAxis" />
    <loc xlink:href="http://xbrl.sec.gov/dei/2013/dei-2013-01-31.xsd#dei_EntityDomain" xlink:type="locator" xlink:label="dei_EntityDomain" />
    <loc xlink:href="http://xbrl.sec.gov/dei/2013/dei-2013-01-31.xsd#dei_LegalEntityAxis" xlink:type="locator" xlink:label="dei_LegalEntityAxis" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ScheduleOfInvestmentsTable" xlink:type="locator" xlink:label="us-gaap_ScheduleOfInvestmentsTable" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_AccountingPoliciesAbstract" xlink:type="locator" xlink:label="us-gaap_AccountingPoliciesAbstract" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AccountingPoliciesAbstract" xlink:to="us-gaap_ScheduleOfInvestmentsTable" order="10010.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfInvestmentsTable" xlink:to="dei_LegalEntityAxis" order="10020.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="dei_LegalEntityAxis" xlink:to="dei_EntityDomain" order="10030.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfInvestmentsTable" xlink:to="us-gaap_StatementScenarioAxis" order="10020.02" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementScenarioAxis" xlink:to="us-gaap_ScenarioUnspecifiedDomain" order="10050.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScenarioUnspecifiedDomain" xlink:to="arwr_WarrantsIssuedMember" order="10070.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfInvestmentsTable" xlink:to="us-gaap_SummaryOfInvestmentsOtherThanInvestmentsInRelatedPartiesByTypeAxis" order="10020.04" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_SummaryOfInvestmentsOtherThanInvestmentsInRelatedPartiesByTypeAxis" xlink:to="us-gaap_SummaryOfInvestmentsByTypeDomain" order="10100.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_SummaryOfInvestmentsByTypeDomain" xlink:to="us-gaap_BondsMember" order="10120.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfInvestmentsTable" xlink:to="us-gaap_ScheduleOfInvestmentsLineItems" order="10140.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfInvestmentsLineItems" xlink:to="us-gaap_CashAndCashEquivalentsAtCarryingValue" order="10180.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfInvestmentsLineItems" xlink:to="us-gaap_DebtInstrumentMaturityDateDescription" order="10200.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfInvestmentsLineItems" xlink:to="us-gaap_Investments" order="10240.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfInvestmentsLineItems" xlink:to="us-gaap_CashAndCashEquivalentsPeriodIncreaseDecrease" order="10280.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfInvestmentsLineItems" xlink:to="us-gaap_ProceedsFromIssuanceOrSaleOfEquity" order="10300.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfInvestmentsLineItems" xlink:to="us-gaap_ProceedsFromIssuanceOfWarrants" order="10340.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfInvestmentsLineItems" xlink:to="us-gaap_PaymentsToAcquireProjects" order="10380.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfInvestmentsLineItems" xlink:to="arwr_OperatingCashOutflow" order="10420.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfInvestmentsLineItems" xlink:to="us-gaap_PaymentsToAcquireOtherPropertyPlantAndEquipment" order="10460.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfInvestmentsLineItems" xlink:to="us-gaap_RestrictedCashAndCashEquivalents" order="10560.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfInvestmentsLineItems" xlink:to="us-gaap_CashFDICInsuredAmount" order="10700.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfInvestmentsLineItems" xlink:to="us-gaap_MarketableSecurities" order="10890.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfInvestmentsLineItems" xlink:to="us-gaap_UnrealizedLossOnSecurities" order="10930.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfInvestmentsLineItems" xlink:to="us-gaap_UnrealizedGainOnSecurities" order="10970.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfInvestmentsLineItems" xlink:to="us-gaap_InvestmentsFairValueDisclosure" order="11010.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfInvestmentsTable" xlink:to="us-gaap_RangeAxis" order="10020.06" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_RangeAxis" xlink:to="us-gaap_RangeMember" order="11080.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_RangeMember" xlink:to="us-gaap_MinimumMember" order="11100.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_RangeMember" xlink:to="us-gaap_MaximumMember" order="11120.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfInvestmentsLineItems" xlink:to="us-gaap_PropertyPlantAndEquipmentUsefulLife" order="11180.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfInvestmentsLineItems" xlink:to="arwr_CostMethodInvestmentAttributableToNoncontrollingInterest" order="11320.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
  </presentationLink>
  <roleRef roleURI="http://www.arrowheadresearch.com/20140331/taxonomy/role/DisclosureInvestmentsSummaryOfShortAndLongTermInvestmentsDetail" xlink:href="arwr-20140331.xsd#Role_DisclosureInvestmentsSummaryOfShortAndLongTermInvestmentsDetail" xlink:type="simple" />
  <presentationLink xlink:type="extended" xlink:role="http://www.arrowheadresearch.com/20140331/taxonomy/role/DisclosureInvestmentsSummaryOfShortAndLongTermInvestmentsDetail">
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_MarketableSecurities" xlink:type="locator" xlink:label="us-gaap_MarketableSecurities" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_MarketableSecuritiesNoncurrent" xlink:type="locator" xlink:label="us-gaap_MarketableSecuritiesNoncurrent" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_MarketableSecuritiesCurrent" xlink:type="locator" xlink:label="us-gaap_MarketableSecuritiesCurrent" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_InvestmentsFairValueDisclosure" xlink:type="locator" xlink:label="us-gaap_InvestmentsFairValueDisclosure" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_UnrealizedLossOnSecurities" xlink:type="locator" xlink:label="us-gaap_UnrealizedLossOnSecurities" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_UnrealizedGainOnSecurities" xlink:type="locator" xlink:label="us-gaap_UnrealizedGainOnSecurities" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ScheduleOfInvestmentsLineItems" xlink:type="locator" xlink:label="us-gaap_ScheduleOfInvestmentsLineItems" />
    <loc xlink:href="arwr-20140331.xsd#arwr_CommercialNotesDueAfterOneYearThroughTwoYearsMember" xlink:type="locator" xlink:label="arwr_CommercialNotesDueAfterOneYearThroughTwoYearsMember" />
    <loc xlink:href="arwr-20140331.xsd#arwr_CommercialNotesDueWithinOneYearMember" xlink:type="locator" xlink:label="arwr_CommercialNotesDueWithinOneYearMember" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_MajorTypesOfDebtAndEquitySecuritiesDomain" xlink:type="locator" xlink:label="us-gaap_MajorTypesOfDebtAndEquitySecuritiesDomain" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis" xlink:type="locator" xlink:label="us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis" />
    <loc xlink:href="http://xbrl.sec.gov/dei/2013/dei-2013-01-31.xsd#dei_EntityDomain" xlink:type="locator" xlink:label="dei_EntityDomain" />
    <loc xlink:href="http://xbrl.sec.gov/dei/2013/dei-2013-01-31.xsd#dei_LegalEntityAxis" xlink:type="locator" xlink:label="dei_LegalEntityAxis" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ScheduleOfInvestmentsTable" xlink:type="locator" xlink:label="us-gaap_ScheduleOfInvestmentsTable" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_EquityAbstract" xlink:type="locator" xlink:label="us-gaap_EquityAbstract" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_EquityAbstract" xlink:to="us-gaap_ScheduleOfInvestmentsTable" order="10010.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfInvestmentsTable" xlink:to="dei_LegalEntityAxis" order="10020.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="dei_LegalEntityAxis" xlink:to="dei_EntityDomain" order="10030.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfInvestmentsTable" xlink:to="us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis" order="10020.02" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_MajorTypesOfDebtAndEquitySecuritiesAxis" xlink:to="us-gaap_MajorTypesOfDebtAndEquitySecuritiesDomain" order="10050.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_MajorTypesOfDebtAndEquitySecuritiesDomain" xlink:to="arwr_CommercialNotesDueWithinOneYearMember" order="10070.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_MajorTypesOfDebtAndEquitySecuritiesDomain" xlink:to="arwr_CommercialNotesDueAfterOneYearThroughTwoYearsMember" order="10090.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfInvestmentsTable" xlink:to="us-gaap_ScheduleOfInvestmentsLineItems" order="10110.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfInvestmentsLineItems" xlink:to="us-gaap_UnrealizedGainOnSecurities" order="10150.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfInvestmentsLineItems" xlink:to="us-gaap_UnrealizedLossOnSecurities" order="10290.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2009/role/negatedLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfInvestmentsLineItems" xlink:to="us-gaap_InvestmentsFairValueDisclosure" order="10430.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfInvestmentsLineItems" xlink:to="us-gaap_MarketableSecuritiesCurrent" order="10650.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfInvestmentsLineItems" xlink:to="us-gaap_MarketableSecuritiesNoncurrent" order="10670.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfInvestmentsLineItems" xlink:to="us-gaap_MarketableSecurities" order="10710.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/totalLabel" />
  </presentationLink>
  <roleRef roleURI="http://www.arrowheadresearch.com/20140331/taxonomy/role/DisclosureSummaryOfPropertyAndEquipmentDetail" xlink:href="arwr-20140331.xsd#Role_DisclosureSummaryOfPropertyAndEquipmentDetail" xlink:type="simple" />
  <presentationLink xlink:type="extended" xlink:role="http://www.arrowheadresearch.com/20140331/taxonomy/role/DisclosureSummaryOfPropertyAndEquipmentDetail">
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_PropertyPlantAndEquipmentNet" xlink:type="locator" xlink:label="us-gaap_PropertyPlantAndEquipmentNet" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment" xlink:type="locator" xlink:label="us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_PropertyPlantAndEquipmentGross" xlink:type="locator" xlink:label="us-gaap_PropertyPlantAndEquipmentGross" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_LeaseholdImprovementsGross" xlink:type="locator" xlink:label="us-gaap_LeaseholdImprovementsGross" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_CapitalizedComputerSoftwareGross" xlink:type="locator" xlink:label="us-gaap_CapitalizedComputerSoftwareGross" />
    <loc xlink:href="arwr-20140331.xsd#arwr_ResearchEquipment" xlink:type="locator" xlink:label="arwr_ResearchEquipment" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_FurnitureAndFixturesGross" xlink:type="locator" xlink:label="us-gaap_FurnitureAndFixturesGross" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_PropertyPlantAndEquipmentLineItems" xlink:type="locator" xlink:label="us-gaap_PropertyPlantAndEquipmentLineItems" />
    <loc xlink:href="http://xbrl.sec.gov/dei/2013/dei-2013-01-31.xsd#dei_EntityDomain" xlink:type="locator" xlink:label="dei_EntityDomain" />
    <loc xlink:href="http://xbrl.sec.gov/dei/2013/dei-2013-01-31.xsd#dei_LegalEntityAxis" xlink:type="locator" xlink:label="dei_LegalEntityAxis" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ScheduleOfPropertyPlantAndEquipmentTable" xlink:type="locator" xlink:label="us-gaap_ScheduleOfPropertyPlantAndEquipmentTable" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedPropertyPlantAndEquipmentAbstract" xlink:type="locator" xlink:label="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedPropertyPlantAndEquipmentAbstract" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedPropertyPlantAndEquipmentAbstract" xlink:to="us-gaap_ScheduleOfPropertyPlantAndEquipmentTable" order="10070.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfPropertyPlantAndEquipmentTable" xlink:to="dei_LegalEntityAxis" order="10080.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="dei_LegalEntityAxis" xlink:to="dei_EntityDomain" order="10090.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfPropertyPlantAndEquipmentTable" xlink:to="us-gaap_PropertyPlantAndEquipmentLineItems" order="10100.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_PropertyPlantAndEquipmentLineItems" xlink:to="us-gaap_FurnitureAndFixturesGross" order="10140.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_PropertyPlantAndEquipmentLineItems" xlink:to="arwr_ResearchEquipment" order="10220.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_PropertyPlantAndEquipmentLineItems" xlink:to="us-gaap_CapitalizedComputerSoftwareGross" order="10300.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_PropertyPlantAndEquipmentLineItems" xlink:to="us-gaap_LeaseholdImprovementsGross" order="10380.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_PropertyPlantAndEquipmentLineItems" xlink:to="us-gaap_PropertyPlantAndEquipmentGross" order="10460.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/totalLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_PropertyPlantAndEquipmentLineItems" xlink:to="us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment" order="10540.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2009/role/negatedLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_PropertyPlantAndEquipmentLineItems" xlink:to="us-gaap_PropertyPlantAndEquipmentNet" order="10620.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/totalLabel" />
  </presentationLink>
  <roleRef roleURI="http://www.arrowheadresearch.com/20140331/taxonomy/role/DisclosureAcquisitionsAdditionalInformationDetail" xlink:href="arwr-20140331.xsd#Role_DisclosureAcquisitionsAdditionalInformationDetail" xlink:type="simple" />
  <presentationLink xlink:type="extended" xlink:role="http://www.arrowheadresearch.com/20140331/taxonomy/role/DisclosureAcquisitionsAdditionalInformationDetail">
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_BusinessCombinationContingentConsiderationArrangementsChangeInAmountOfContingentConsiderationLiability1" xlink:type="locator" xlink:label="us-gaap_BusinessCombinationContingentConsiderationArrangementsChangeInAmountOfContingentConsiderationLiability1" />
    <loc xlink:href="arwr-20140331.xsd#arwr_PresentValueOfContingentAcquisitionConsideration" xlink:type="locator" xlink:label="arwr_PresentValueOfContingentAcquisitionConsideration" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_BusinessCombinationContingentConsiderationArrangementsRangeOfOutcomesValueHigh" xlink:type="locator" xlink:label="us-gaap_BusinessCombinationContingentConsiderationArrangementsRangeOfOutcomesValueHigh" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_BusinessCombinationContingentConsiderationArrangementsRangeOfOutcomesValueLow" xlink:type="locator" xlink:label="us-gaap_BusinessCombinationContingentConsiderationArrangementsRangeOfOutcomesValueLow" />
    <loc xlink:href="arwr-20140331.xsd#arwr_ObligationToPayRoyalties" xlink:type="locator" xlink:label="arwr_ObligationToPayRoyalties" />
    <loc xlink:href="arwr-20140331.xsd#arwr_PercentageOfRoyaltyLiability" xlink:type="locator" xlink:label="arwr_PercentageOfRoyaltyLiability" />
    <loc xlink:href="arwr-20140331.xsd#arwr_ApplicableOutLicenseTerm" xlink:type="locator" xlink:label="arwr_ApplicableOutLicenseTerm" />
    <loc xlink:href="arwr-20140331.xsd#arwr_BusinessAcquisitionEquityInterestsIssuedNumberOfSharesIssued" xlink:type="locator" xlink:label="arwr_BusinessAcquisitionEquityInterestsIssuedNumberOfSharesIssued" />
    <loc xlink:href="arwr-20140331.xsd#arwr_BusinessCombinationConsiderationPromissoryNoteIssued" xlink:type="locator" xlink:label="arwr_BusinessCombinationConsiderationPromissoryNoteIssued" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_BusinessAcquisitionLineItems" xlink:type="locator" xlink:label="us-gaap_BusinessAcquisitionLineItems" />
    <loc xlink:href="arwr-20140331.xsd#arwr_RocheMadisonMember" xlink:type="locator" xlink:label="arwr_RocheMadisonMember" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_BusinessAcquisitionAcquireeDomain" xlink:type="locator" xlink:label="us-gaap_BusinessAcquisitionAcquireeDomain" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_BusinessAcquisitionAxis" xlink:type="locator" xlink:label="us-gaap_BusinessAcquisitionAxis" />
    <loc xlink:href="http://xbrl.sec.gov/dei/2013/dei-2013-01-31.xsd#dei_EntityDomain" xlink:type="locator" xlink:label="dei_EntityDomain" />
    <loc xlink:href="http://xbrl.sec.gov/dei/2013/dei-2013-01-31.xsd#dei_LegalEntityAxis" xlink:type="locator" xlink:label="dei_LegalEntityAxis" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable" xlink:type="locator" xlink:label="us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_BusinessCombinationsAbstract" xlink:type="locator" xlink:label="us-gaap_BusinessCombinationsAbstract" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_BusinessCombinationsAbstract" xlink:to="us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable" order="10010.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable" xlink:to="dei_LegalEntityAxis" order="10020.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="dei_LegalEntityAxis" xlink:to="dei_EntityDomain" order="10030.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable" xlink:to="us-gaap_BusinessAcquisitionAxis" order="10020.02" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_BusinessAcquisitionAxis" xlink:to="us-gaap_BusinessAcquisitionAcquireeDomain" order="10050.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_BusinessAcquisitionAcquireeDomain" xlink:to="arwr_RocheMadisonMember" order="10070.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable" xlink:to="us-gaap_BusinessAcquisitionLineItems" order="10110.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_BusinessAcquisitionLineItems" xlink:to="arwr_BusinessCombinationConsiderationPromissoryNoteIssued" order="10150.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_BusinessAcquisitionLineItems" xlink:to="arwr_BusinessAcquisitionEquityInterestsIssuedNumberOfSharesIssued" order="10190.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_BusinessAcquisitionLineItems" xlink:to="arwr_ApplicableOutLicenseTerm" order="10340.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_BusinessAcquisitionLineItems" xlink:to="arwr_PercentageOfRoyaltyLiability" order="10490.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_BusinessAcquisitionLineItems" xlink:to="arwr_ObligationToPayRoyalties" order="10530.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_BusinessAcquisitionLineItems" xlink:to="us-gaap_BusinessCombinationContingentConsiderationArrangementsRangeOfOutcomesValueLow" order="10700.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_BusinessAcquisitionLineItems" xlink:to="us-gaap_BusinessCombinationContingentConsiderationArrangementsRangeOfOutcomesValueHigh" order="10740.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_BusinessAcquisitionLineItems" xlink:to="arwr_PresentValueOfContingentAcquisitionConsideration" order="10780.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_BusinessAcquisitionLineItems" xlink:to="us-gaap_BusinessCombinationContingentConsiderationArrangementsChangeInAmountOfContingentConsiderationLiability1" order="10820.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
  </presentationLink>
  <roleRef roleURI="http://www.arrowheadresearch.com/20140331/taxonomy/role/DisclosureIntangibleAssetsAdditionalInformationDetail" xlink:href="arwr-20140331.xsd#Role_DisclosureIntangibleAssetsAdditionalInformationDetail" xlink:type="simple" />
  <presentationLink xlink:type="extended" xlink:role="http://www.arrowheadresearch.com/20140331/taxonomy/role/DisclosureIntangibleAssetsAdditionalInformationDetail">
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseAfterYearFive" xlink:type="locator" xlink:label="us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseAfterYearFive" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearThree" xlink:type="locator" xlink:label="us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearThree" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearTwo" xlink:type="locator" xlink:label="us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearTwo" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseNextTwelveMonths" xlink:type="locator" xlink:label="us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseNextTwelveMonths" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetUsefulLife" xlink:type="locator" xlink:label="us-gaap_FiniteLivedIntangibleAssetUsefulLife" />
    <loc xlink:href="arwr-20140331.xsd#arwr_ExpectedAmortizationExpenseLineItems" xlink:type="locator" xlink:label="arwr_ExpectedAmortizationExpenseLineItems" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_MaximumMember" xlink:type="locator" xlink:label="us-gaap_MaximumMember" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_MinimumMember" xlink:type="locator" xlink:label="us-gaap_MinimumMember" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_RangeMember" xlink:type="locator" xlink:label="us-gaap_RangeMember" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_RangeAxis" xlink:type="locator" xlink:label="us-gaap_RangeAxis" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_PatentsMember" xlink:type="locator" xlink:label="us-gaap_PatentsMember" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_LicensingAgreementsMember" xlink:type="locator" xlink:label="us-gaap_LicensingAgreementsMember" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain" xlink:type="locator" xlink:label="us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis" xlink:type="locator" xlink:label="us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis" />
    <loc xlink:href="http://xbrl.sec.gov/dei/2013/dei-2013-01-31.xsd#dei_EntityDomain" xlink:type="locator" xlink:label="dei_EntityDomain" />
    <loc xlink:href="http://xbrl.sec.gov/dei/2013/dei-2013-01-31.xsd#dei_LegalEntityAxis" xlink:type="locator" xlink:label="dei_LegalEntityAxis" />
    <loc xlink:href="arwr-20140331.xsd#arwr_ExpectedAmortizationExpenseTable" xlink:type="locator" xlink:label="arwr_ExpectedAmortizationExpenseTable" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_GoodwillAndIntangibleAssetsDisclosureAbstract" xlink:type="locator" xlink:label="us-gaap_GoodwillAndIntangibleAssetsDisclosureAbstract" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_GoodwillAndIntangibleAssetsDisclosureAbstract" xlink:to="arwr_ExpectedAmortizationExpenseTable" order="10010.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="arwr_ExpectedAmortizationExpenseTable" xlink:to="dei_LegalEntityAxis" order="10020.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="dei_LegalEntityAxis" xlink:to="dei_EntityDomain" order="10030.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="arwr_ExpectedAmortizationExpenseTable" xlink:to="us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis" order="10020.02" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis" xlink:to="us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain" order="10050.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain" xlink:to="us-gaap_LicensingAgreementsMember" order="10070.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain" xlink:to="us-gaap_PatentsMember" order="10090.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="arwr_ExpectedAmortizationExpenseTable" xlink:to="us-gaap_RangeAxis" order="10020.04" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_RangeAxis" xlink:to="us-gaap_RangeMember" order="10140.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_RangeMember" xlink:to="us-gaap_MinimumMember" order="10160.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_RangeMember" xlink:to="us-gaap_MaximumMember" order="10180.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="arwr_ExpectedAmortizationExpenseTable" xlink:to="arwr_ExpectedAmortizationExpenseLineItems" order="10200.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="arwr_ExpectedAmortizationExpenseLineItems" xlink:to="us-gaap_FiniteLivedIntangibleAssetUsefulLife" order="10240.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="arwr_ExpectedAmortizationExpenseLineItems" xlink:to="us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseNextTwelveMonths" order="10440.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="arwr_ExpectedAmortizationExpenseLineItems" xlink:to="us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearTwo" order="10580.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="arwr_ExpectedAmortizationExpenseLineItems" xlink:to="us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseYearThree" order="10720.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="arwr_ExpectedAmortizationExpenseLineItems" xlink:to="us-gaap_FiniteLivedIntangibleAssetsAmortizationExpenseAfterYearFive" order="10860.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
  </presentationLink>
  <roleRef roleURI="http://www.arrowheadresearch.com/20140331/taxonomy/role/DisclosureIntangibleAssetsScheduleOfIntangibleAssetDetail" xlink:href="arwr-20140331.xsd#Role_DisclosureIntangibleAssetsScheduleOfIntangibleAssetDetail" xlink:type="simple" />
  <presentationLink xlink:type="extended" xlink:role="http://www.arrowheadresearch.com/20140331/taxonomy/role/DisclosureIntangibleAssetsScheduleOfIntangibleAssetDetail">
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_IntangibleAssetsNetExcludingGoodwill" xlink:type="locator" xlink:label="us-gaap_IntangibleAssetsNetExcludingGoodwill_li0l2" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_AmortizationOfIntangibleAssets" xlink:type="locator" xlink:label="us-gaap_AmortizationOfIntangibleAssets_li0l2" />
    <loc xlink:href="arwr-20140331.xsd#arwr_IntangibleAssetsAdditions" xlink:type="locator" xlink:label="arwr_IntangibleAssetsAdditions" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_IntangibleAssetsNetExcludingGoodwill" xlink:type="locator" xlink:label="us-gaap_IntangibleAssetsNetExcludingGoodwill" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ImpairmentOfIntangibleAssetsFinitelived" xlink:type="locator" xlink:label="us-gaap_ImpairmentOfIntangibleAssetsFinitelived" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsNet" xlink:type="locator" xlink:label="us-gaap_FiniteLivedIntangibleAssetsNet_li0l2" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_AmortizationOfIntangibleAssets" xlink:type="locator" xlink:label="us-gaap_AmortizationOfIntangibleAssets" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_FinitelivedIntangibleAssetsAcquired1" xlink:type="locator" xlink:label="us-gaap_FinitelivedIntangibleAssetsAcquired1" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_FiniteLivedIntangibleAssetsNet" xlink:type="locator" xlink:label="us-gaap_FiniteLivedIntangibleAssetsNet" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ImpairmentOfIntangibleAssetsIndefinitelivedExcludingGoodwill" xlink:type="locator" xlink:label="us-gaap_ImpairmentOfIntangibleAssetsIndefinitelivedExcludingGoodwill" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_IndefiniteLivedIntangibleAssetsExcludingGoodwill" xlink:type="locator" xlink:label="us-gaap_IndefiniteLivedIntangibleAssetsExcludingGoodwill_li0l2" />
    <loc xlink:href="arwr-20140331.xsd#arwr_IndefiniteLivedIntangibleAssetsAccumulatedAmortization" xlink:type="locator" xlink:label="arwr_IndefiniteLivedIntangibleAssetsAccumulatedAmortization" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_IndefinitelivedIntangibleAssetsAcquired" xlink:type="locator" xlink:label="us-gaap_IndefinitelivedIntangibleAssetsAcquired" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_IndefiniteLivedIntangibleAssetsExcludingGoodwill" xlink:type="locator" xlink:label="us-gaap_IndefiniteLivedIntangibleAssetsExcludingGoodwill" />
    <loc xlink:href="arwr-20140331.xsd#arwr_FiniteLivedAndIndefiniteLivedIntangibleAssetsLineItems" xlink:type="locator" xlink:label="arwr_FiniteLivedAndIndefiniteLivedIntangibleAssetsLineItems" />
    <loc xlink:href="arwr-20140331.xsd#arwr_AlvosTherapeuticsMember" xlink:type="locator" xlink:label="arwr_AlvosTherapeuticsMember" />
    <loc xlink:href="arwr-20140331.xsd#arwr_RocheMadisonMember" xlink:type="locator" xlink:label="arwr_RocheMadisonMember" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_BusinessAcquisitionAcquireeDomain" xlink:type="locator" xlink:label="us-gaap_BusinessAcquisitionAcquireeDomain" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_BusinessAcquisitionAxis" xlink:type="locator" xlink:label="us-gaap_BusinessAcquisitionAxis" />
    <loc xlink:href="http://xbrl.sec.gov/dei/2013/dei-2013-01-31.xsd#dei_EntityDomain" xlink:type="locator" xlink:label="dei_EntityDomain" />
    <loc xlink:href="http://xbrl.sec.gov/dei/2013/dei-2013-01-31.xsd#dei_LegalEntityAxis" xlink:type="locator" xlink:label="dei_LegalEntityAxis" />
    <loc xlink:href="arwr-20140331.xsd#arwr_ScheduleOfFiniteLivedAndIndefiniteLivedIntangibleAssetsTable" xlink:type="locator" xlink:label="arwr_ScheduleOfFiniteLivedAndIndefiniteLivedIntangibleAssetsTable" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_GoodwillAndIntangibleAssetsDisclosureAbstract" xlink:type="locator" xlink:label="us-gaap_GoodwillAndIntangibleAssetsDisclosureAbstract" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_GoodwillAndIntangibleAssetsDisclosureAbstract" xlink:to="arwr_ScheduleOfFiniteLivedAndIndefiniteLivedIntangibleAssetsTable" order="10010.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="arwr_ScheduleOfFiniteLivedAndIndefiniteLivedIntangibleAssetsTable" xlink:to="dei_LegalEntityAxis" order="10020.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="dei_LegalEntityAxis" xlink:to="dei_EntityDomain" order="10030.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="arwr_ScheduleOfFiniteLivedAndIndefiniteLivedIntangibleAssetsTable" xlink:to="us-gaap_BusinessAcquisitionAxis" order="10020.02" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_BusinessAcquisitionAxis" xlink:to="us-gaap_BusinessAcquisitionAcquireeDomain" order="10050.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_BusinessAcquisitionAcquireeDomain" xlink:to="arwr_RocheMadisonMember" order="10070.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_BusinessAcquisitionAcquireeDomain" xlink:to="arwr_AlvosTherapeuticsMember" order="10090.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="arwr_ScheduleOfFiniteLivedAndIndefiniteLivedIntangibleAssetsTable" xlink:to="arwr_FiniteLivedAndIndefiniteLivedIntangibleAssetsLineItems" order="10110.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="arwr_FiniteLivedAndIndefiniteLivedIntangibleAssetsLineItems" xlink:to="us-gaap_IndefiniteLivedIntangibleAssetsExcludingGoodwill" order="10150.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/periodStartLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="arwr_FiniteLivedAndIndefiniteLivedIntangibleAssetsLineItems" xlink:to="us-gaap_IndefinitelivedIntangibleAssetsAcquired" order="10250.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="arwr_FiniteLivedAndIndefiniteLivedIntangibleAssetsLineItems" xlink:to="arwr_IndefiniteLivedIntangibleAssetsAccumulatedAmortization" order="10450.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2009/role/negatedLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="arwr_FiniteLivedAndIndefiniteLivedIntangibleAssetsLineItems" xlink:to="us-gaap_IndefiniteLivedIntangibleAssetsExcludingGoodwill_li0l2" order="10550.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/periodEndLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="arwr_FiniteLivedAndIndefiniteLivedIntangibleAssetsLineItems" xlink:to="us-gaap_ImpairmentOfIntangibleAssetsIndefinitelivedExcludingGoodwill" order="10650.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2009/role/negatedLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="arwr_FiniteLivedAndIndefiniteLivedIntangibleAssetsLineItems" xlink:to="us-gaap_FiniteLivedIntangibleAssetsNet" order="11280.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/periodStartLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="arwr_FiniteLivedAndIndefiniteLivedIntangibleAssetsLineItems" xlink:to="us-gaap_FinitelivedIntangibleAssetsAcquired1" order="11380.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="arwr_FiniteLivedAndIndefiniteLivedIntangibleAssetsLineItems" xlink:to="us-gaap_AmortizationOfIntangibleAssets" order="11580.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2009/role/negatedLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="arwr_FiniteLivedAndIndefiniteLivedIntangibleAssetsLineItems" xlink:to="us-gaap_FiniteLivedIntangibleAssetsNet_li0l2" order="11680.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/periodEndLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="arwr_FiniteLivedAndIndefiniteLivedIntangibleAssetsLineItems" xlink:to="us-gaap_ImpairmentOfIntangibleAssetsFinitelived" order="11780.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2009/role/negatedLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="arwr_FiniteLivedAndIndefiniteLivedIntangibleAssetsLineItems" xlink:to="us-gaap_IntangibleAssetsNetExcludingGoodwill" order="12410.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/periodStartLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="arwr_FiniteLivedAndIndefiniteLivedIntangibleAssetsLineItems" xlink:to="arwr_IntangibleAssetsAdditions" order="12510.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="arwr_FiniteLivedAndIndefiniteLivedIntangibleAssetsLineItems" xlink:to="us-gaap_AmortizationOfIntangibleAssets_li0l2" order="12710.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2009/role/negatedTerseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="arwr_FiniteLivedAndIndefiniteLivedIntangibleAssetsLineItems" xlink:to="us-gaap_IntangibleAssetsNetExcludingGoodwill_li0l2" order="12790.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/periodEndLabel" />
  </presentationLink>
  <roleRef roleURI="http://www.arrowheadresearch.com/20140331/taxonomy/role/DisclosureInvestmentInSubsidiariesAdditionalInformationDetail" xlink:href="arwr-20140331.xsd#Role_DisclosureInvestmentInSubsidiariesAdditionalInformationDetail" xlink:type="simple" />
  <presentationLink xlink:type="extended" xlink:role="http://www.arrowheadresearch.com/20140331/taxonomy/role/DisclosureInvestmentInSubsidiariesAdditionalInformationDetail">
    <loc xlink:href="arwr-20140331.xsd#arwr_InvestmentInPreferredStockByOutsider" xlink:type="locator" xlink:label="arwr_InvestmentInPreferredStockByOutsider" />
    <loc xlink:href="arwr-20140331.xsd#arwr_InvestmentInPreferredStock" xlink:type="locator" xlink:label="arwr_InvestmentInPreferredStock" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ProceedsFromIssuanceOfPreferredStockAndPreferenceStock" xlink:type="locator" xlink:label="us-gaap_ProceedsFromIssuanceOfPreferredStockAndPreferenceStock" />
    <loc xlink:href="arwr-20140331.xsd#arwr_AblarisTherapeuticsMember" xlink:type="locator" xlink:label="arwr_AblarisTherapeuticsMember" />
    <loc xlink:href="arwr-20140331.xsd#arwr_EquityMethodInvestmentOwnershipPercentageOnDilutiveBasis" xlink:type="locator" xlink:label="arwr_EquityMethodInvestmentOwnershipPercentageOnDilutiveBasis" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_EquityMethodInvestmentOwnershipPercentage" xlink:type="locator" xlink:label="us-gaap_EquityMethodInvestmentOwnershipPercentage" />
    <loc xlink:href="arwr-20140331.xsd#arwr_StatedPercentageOfNotesAndAdvances" xlink:type="locator" xlink:label="arwr_StatedPercentageOfNotesAndAdvances" />
    <loc xlink:href="arwr-20140331.xsd#arwr_AmountOwedBySubsidiary" xlink:type="locator" xlink:label="arwr_AmountOwedBySubsidiary" />
    <loc xlink:href="arwr-20140331.xsd#arwr_OutstandingBalanceOfPromissoryNote" xlink:type="locator" xlink:label="arwr_OutstandingBalanceOfPromissoryNote" />
    <loc xlink:href="arwr-20140331.xsd#arwr_CalandoPharmaceuticalsIncMember" xlink:type="locator" xlink:label="arwr_CalandoPharmaceuticalsIncMember" />
    <loc xlink:href="arwr-20140331.xsd#arwr_OwnershipPercentageInSubsidiary" xlink:type="locator" xlink:label="arwr_OwnershipPercentageInSubsidiary" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ScheduleOfInvestmentsLineItems" xlink:type="locator" xlink:label="us-gaap_ScheduleOfInvestmentsLineItems" />
    <loc xlink:href="http://xbrl.sec.gov/dei/2013/dei-2013-01-31.xsd#dei_EntityDomain" xlink:type="locator" xlink:label="dei_EntityDomain" />
    <loc xlink:href="http://xbrl.sec.gov/dei/2013/dei-2013-01-31.xsd#dei_LegalEntityAxis" xlink:type="locator" xlink:label="dei_LegalEntityAxis" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ScheduleOfInvestmentsTable" xlink:type="locator" xlink:label="us-gaap_ScheduleOfInvestmentsTable" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_InvestmentsAllOtherInvestmentsAbstract" xlink:type="locator" xlink:label="us-gaap_InvestmentsAllOtherInvestmentsAbstract" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_InvestmentsAllOtherInvestmentsAbstract" xlink:to="us-gaap_ScheduleOfInvestmentsTable" order="10010.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfInvestmentsTable" xlink:to="dei_LegalEntityAxis" order="10020.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="dei_LegalEntityAxis" xlink:to="dei_EntityDomain" order="10030.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfInvestmentsTable" xlink:to="us-gaap_ScheduleOfInvestmentsLineItems" order="10040.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfInvestmentsLineItems" xlink:to="arwr_OwnershipPercentageInSubsidiary" order="10080.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="dei_EntityDomain" xlink:to="arwr_CalandoPharmaceuticalsIncMember" order="10170.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfInvestmentsLineItems" xlink:to="arwr_OutstandingBalanceOfPromissoryNote" order="10230.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfInvestmentsLineItems" xlink:to="arwr_AmountOwedBySubsidiary" order="10400.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfInvestmentsLineItems" xlink:to="arwr_StatedPercentageOfNotesAndAdvances" order="10440.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfInvestmentsLineItems" xlink:to="us-gaap_EquityMethodInvestmentOwnershipPercentage" order="10610.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfInvestmentsLineItems" xlink:to="arwr_EquityMethodInvestmentOwnershipPercentageOnDilutiveBasis" order="10650.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="dei_EntityDomain" xlink:to="arwr_AblarisTherapeuticsMember" order="10740.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfInvestmentsLineItems" xlink:to="us-gaap_ProceedsFromIssuanceOfPreferredStockAndPreferenceStock" order="10840.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfInvestmentsLineItems" xlink:to="arwr_InvestmentInPreferredStock" order="10900.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfInvestmentsLineItems" xlink:to="arwr_InvestmentInPreferredStockByOutsider" order="10960.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
  </presentationLink>
  <roleRef roleURI="http://www.arrowheadresearch.com/20140331/taxonomy/role/DisclosureNotesPayableAdditionalInformationDetail" xlink:href="arwr-20140331.xsd#Role_DisclosureNotesPayableAdditionalInformationDetail" xlink:type="simple" />
  <presentationLink xlink:type="extended" xlink:role="http://www.arrowheadresearch.com/20140331/taxonomy/role/DisclosureNotesPayableAdditionalInformationDetail">
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_AccountsPayableAndAccruedLiabilitiesCurrent" xlink:type="locator" xlink:label="us-gaap_AccountsPayableAndAccruedLiabilitiesCurrent" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DebtInstrumentCarryingAmount" xlink:type="locator" xlink:label="us-gaap_DebtInstrumentCarryingAmount" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DebtInstrumentInterestRateDuringPeriod" xlink:type="locator" xlink:label="us-gaap_DebtInstrumentInterestRateDuringPeriod" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DebtInstrumentInterestRateStatedPercentage" xlink:type="locator" xlink:label="us-gaap_DebtInstrumentInterestRateStatedPercentage" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DebtInstrumentPaymentTerms" xlink:type="locator" xlink:label="us-gaap_DebtInstrumentPaymentTerms" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DebtInstrumentMaturityDate" xlink:type="locator" xlink:label="us-gaap_DebtInstrumentMaturityDate" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DebtConversionConvertedInstrumentSharesIssued1" xlink:type="locator" xlink:label="us-gaap_DebtConversionConvertedInstrumentSharesIssued1" />
    <loc xlink:href="arwr-20140331.xsd#arwr_PrincipalAmountOfNoteNotConvertedInToShares" xlink:type="locator" xlink:label="arwr_PrincipalAmountOfNoteNotConvertedInToShares" />
    <loc xlink:href="arwr-20140331.xsd#arwr_AdditionalInvestmentInNotesOffering" xlink:type="locator" xlink:label="arwr_AdditionalInvestmentInNotesOffering" />
    <loc xlink:href="arwr-20140331.xsd#arwr_InvestInNotesOffering" xlink:type="locator" xlink:label="arwr_InvestInNotesOffering" />
    <loc xlink:href="arwr-20140331.xsd#arwr_UnsecuredConvertiblePromissoryNoteAgreements" xlink:type="locator" xlink:label="arwr_UnsecuredConvertiblePromissoryNoteAgreements" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ClassOfStockLineItems" xlink:type="locator" xlink:label="us-gaap_ClassOfStockLineItems" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_SeriesAPreferredStockMember" xlink:type="locator" xlink:label="us-gaap_SeriesAPreferredStockMember" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ClassOfStockDomain" xlink:type="locator" xlink:label="us-gaap_ClassOfStockDomain" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_StatementClassOfStockAxis" xlink:type="locator" xlink:label="us-gaap_StatementClassOfStockAxis" />
    <loc xlink:href="arwr-20140331.xsd#arwr_CalandoMember" xlink:type="locator" xlink:label="arwr_CalandoMember" />
    <loc xlink:href="http://xbrl.sec.gov/dei/2013/dei-2013-01-31.xsd#dei_EntityDomain" xlink:type="locator" xlink:label="dei_EntityDomain" />
    <loc xlink:href="http://xbrl.sec.gov/dei/2013/dei-2013-01-31.xsd#dei_LegalEntityAxis" xlink:type="locator" xlink:label="dei_LegalEntityAxis" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ScheduleOfStockByClassTable" xlink:type="locator" xlink:label="us-gaap_ScheduleOfStockByClassTable" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_StockholdersEquityNoteAbstract" xlink:type="locator" xlink:label="us-gaap_StockholdersEquityNoteAbstract" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StockholdersEquityNoteAbstract" xlink:to="us-gaap_ScheduleOfStockByClassTable" order="10010.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfStockByClassTable" xlink:to="dei_LegalEntityAxis" order="10020.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="dei_LegalEntityAxis" xlink:to="dei_EntityDomain" order="10030.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="dei_EntityDomain" xlink:to="arwr_CalandoMember" order="10070.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfStockByClassTable" xlink:to="us-gaap_StatementClassOfStockAxis" order="10020.02" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementClassOfStockAxis" xlink:to="us-gaap_ClassOfStockDomain" order="10100.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfStockDomain" xlink:to="us-gaap_SeriesAPreferredStockMember" order="10120.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfStockByClassTable" xlink:to="us-gaap_ClassOfStockLineItems" order="10140.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfStockLineItems" xlink:to="arwr_UnsecuredConvertiblePromissoryNoteAgreements" order="10180.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfStockLineItems" xlink:to="arwr_InvestInNotesOffering" order="10220.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfStockLineItems" xlink:to="arwr_AdditionalInvestmentInNotesOffering" order="10260.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfStockLineItems" xlink:to="arwr_PrincipalAmountOfNoteNotConvertedInToShares" order="10300.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfStockLineItems" xlink:to="us-gaap_DebtConversionConvertedInstrumentSharesIssued1" order="10340.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfStockLineItems" xlink:to="us-gaap_DebtInstrumentMaturityDate" order="10380.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfStockLineItems" xlink:to="us-gaap_DebtInstrumentPaymentTerms" order="10420.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfStockLineItems" xlink:to="us-gaap_DebtInstrumentInterestRateStatedPercentage" order="10460.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfStockLineItems" xlink:to="us-gaap_DebtInstrumentInterestRateDuringPeriod" order="10500.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfStockLineItems" xlink:to="us-gaap_DebtInstrumentCarryingAmount" order="10540.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfStockLineItems" xlink:to="us-gaap_AccountsPayableAndAccruedLiabilitiesCurrent" order="10580.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
  </presentationLink>
  <roleRef roleURI="http://www.arrowheadresearch.com/20140331/taxonomy/role/DisclosureStockholdersEquityAdditionalInformationDetail" xlink:href="arwr-20140331.xsd#Role_DisclosureStockholdersEquityAdditionalInformationDetail" xlink:type="simple" />
  <presentationLink xlink:type="extended" xlink:role="http://www.arrowheadresearch.com/20140331/taxonomy/role/DisclosureStockholdersEquityAdditionalInformationDetail">
    <loc xlink:href="arwr-20140331.xsd#arwr_AggregatePriceOnIssuanceOrSaleOfEquity" xlink:type="locator" xlink:label="arwr_AggregatePriceOnIssuanceOrSaleOfEquity" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_SeriesCPreferredStockMember" xlink:type="locator" xlink:label="us-gaap_SeriesCPreferredStockMember" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ProceedsFromIssuanceOrSaleOfEquity" xlink:type="locator" xlink:label="us-gaap_ProceedsFromIssuanceOrSaleOfEquity" />
    <loc xlink:href="arwr-20140331.xsd#arwr_ConversionPricePerShare" xlink:type="locator" xlink:label="arwr_ConversionPricePerShare" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_CommonStockMember" xlink:type="locator" xlink:label="us-gaap_CommonStockMember" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_EquityComponentDomain" xlink:type="locator" xlink:label="us-gaap_EquityComponentDomain" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_StatementEquityComponentsAxis" xlink:type="locator" xlink:label="us-gaap_StatementEquityComponentsAxis" />
    <loc xlink:href="arwr-20140331.xsd#arwr_ConvertiblePreferredStockSeriesBMember" xlink:type="locator" xlink:label="arwr_ConvertiblePreferredStockSeriesBMember" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights" xlink:type="locator" xlink:label="us-gaap_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights" />
    <loc xlink:href="arwr-20140331.xsd#arwr_CommonStockExercisePrice" xlink:type="locator" xlink:label="arwr_CommonStockExercisePrice" />
    <loc xlink:href="arwr-20140331.xsd#arwr_WarrantToPurchaseShareOfCommonStock" xlink:type="locator" xlink:label="arwr_WarrantToPurchaseShareOfCommonStock" />
    <loc xlink:href="arwr-20140331.xsd#arwr_UnitSoldDescription" xlink:type="locator" xlink:label="arwr_UnitSoldDescription" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ProceedsFromIssuanceOfCommonStock" xlink:type="locator" xlink:label="us-gaap_ProceedsFromIssuanceOfCommonStock" />
    <loc xlink:href="arwr-20140331.xsd#arwr_AggregatePurchasePriceOnIssuanceOfCommonStockToBeReceived" xlink:type="locator" xlink:label="arwr_AggregatePurchasePriceOnIssuanceOfCommonStockToBeReceived" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_StockIssuedDuringPeriodSharesConversionOfConvertibleSecurities" xlink:type="locator" xlink:label="us-gaap_StockIssuedDuringPeriodSharesConversionOfConvertibleSecurities" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ConversionOfStockSharesConverted1" xlink:type="locator" xlink:label="us-gaap_ConversionOfStockSharesConverted1" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_StockIssuedDuringPeriodSharesNewIssues" xlink:type="locator" xlink:label="us-gaap_StockIssuedDuringPeriodSharesNewIssues" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ProceedsFromIssuanceOfPreferredStockAndPreferenceStock" xlink:type="locator" xlink:label="us-gaap_ProceedsFromIssuanceOfPreferredStockAndPreferenceStock" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_SaleOfStockPricePerShare" xlink:type="locator" xlink:label="us-gaap_SaleOfStockPricePerShare" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_SeriesAPreferredStockMember" xlink:type="locator" xlink:label="us-gaap_SeriesAPreferredStockMember" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ClassOfStockDomain" xlink:type="locator" xlink:label="us-gaap_ClassOfStockDomain" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_StatementClassOfStockAxis" xlink:type="locator" xlink:label="us-gaap_StatementClassOfStockAxis" />
    <loc xlink:href="arwr-20140331.xsd#arwr_SubscriptionAgreementMember" xlink:type="locator" xlink:label="arwr_SubscriptionAgreementMember" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ScenarioUnspecifiedDomain" xlink:type="locator" xlink:label="us-gaap_ScenarioUnspecifiedDomain" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_StatementScenarioAxis" xlink:type="locator" xlink:label="us-gaap_StatementScenarioAxis" />
    <loc xlink:href="arwr-20140331.xsd#arwr_CashDrawnFromFacility" xlink:type="locator" xlink:label="arwr_CashDrawnFromFacility" />
    <loc xlink:href="arwr-20140331.xsd#arwr_EquityCommitmentAgreementPeriod" xlink:type="locator" xlink:label="arwr_EquityCommitmentAgreementPeriod" />
    <loc xlink:href="arwr-20140331.xsd#arwr_MaximumEquityCommitmentAmountUnderAgreement" xlink:type="locator" xlink:label="arwr_MaximumEquityCommitmentAmountUnderAgreement" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_LimitedLiabilityCompanyMember" xlink:type="locator" xlink:label="us-gaap_LimitedLiabilityCompanyMember" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_RelatedPartyDomain" xlink:type="locator" xlink:label="us-gaap_RelatedPartyDomain" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_RelatedPartyTransactionsByRelatedPartyAxis" xlink:type="locator" xlink:label="us-gaap_RelatedPartyTransactionsByRelatedPartyAxis" />
    <loc xlink:href="arwr-20140331.xsd#arwr_ThresholdPercentageOfCommonStockOwnershipUponPreferredStockConversion" xlink:type="locator" xlink:label="arwr_ThresholdPercentageOfCommonStockOwnershipUponPreferredStockConversion" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DeferredCompensationArrangementWithIndividualCommonStockReservedForFutureIssuance" xlink:type="locator" xlink:label="us-gaap_DeferredCompensationArrangementWithIndividualCommonStockReservedForFutureIssuance" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_PreferredStockSharesOutstanding" xlink:type="locator" xlink:label="us-gaap_PreferredStockSharesOutstanding" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_CommonStockSharesOutstanding" xlink:type="locator" xlink:label="us-gaap_CommonStockSharesOutstanding" />
    <loc xlink:href="arwr-20140331.xsd#arwr_TwoThousandFourEquityIncentivePlanTwoThousandStockOptionPlanAndInducementGrantsMember" xlink:type="locator" xlink:label="arwr_TwoThousandFourEquityIncentivePlanTwoThousandStockOptionPlanAndInducementGrantsMember" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_PlanNameDomain" xlink:type="locator" xlink:label="us-gaap_PlanNameDomain" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_PlanNameAxis" xlink:type="locator" xlink:label="us-gaap_PlanNameAxis" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_PreferredStockParOrStatedValuePerShare" xlink:type="locator" xlink:label="us-gaap_PreferredStockParOrStatedValuePerShare" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_PreferredStockSharesAuthorized" xlink:type="locator" xlink:label="us-gaap_PreferredStockSharesAuthorized" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_CommonStockParOrStatedValuePerShare" xlink:type="locator" xlink:label="us-gaap_CommonStockParOrStatedValuePerShare" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_CommonStockSharesAuthorized" xlink:type="locator" xlink:label="us-gaap_CommonStockSharesAuthorized" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_CapitalUnitsAuthorized" xlink:type="locator" xlink:label="us-gaap_CapitalUnitsAuthorized" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:type="locator" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" />
    <loc xlink:href="http://xbrl.sec.gov/dei/2013/dei-2013-01-31.xsd#dei_EntityDomain" xlink:type="locator" xlink:label="dei_EntityDomain" />
    <loc xlink:href="http://xbrl.sec.gov/dei/2013/dei-2013-01-31.xsd#dei_LegalEntityAxis" xlink:type="locator" xlink:label="dei_LegalEntityAxis" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable" xlink:type="locator" xlink:label="us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_EquityAbstract" xlink:type="locator" xlink:label="us-gaap_EquityAbstract" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_EquityAbstract" xlink:to="us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable" order="10010.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable" xlink:to="dei_LegalEntityAxis" order="10020.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="dei_LegalEntityAxis" xlink:to="dei_EntityDomain" order="10030.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" order="10040.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="us-gaap_CapitalUnitsAuthorized" order="10080.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="us-gaap_CommonStockSharesAuthorized" order="10120.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="us-gaap_CommonStockParOrStatedValuePerShare" order="10140.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="us-gaap_PreferredStockSharesAuthorized" order="10160.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="us-gaap_PreferredStockParOrStatedValuePerShare" order="10180.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable" xlink:to="us-gaap_PlanNameAxis" order="10020.02" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_PlanNameAxis" xlink:to="us-gaap_PlanNameDomain" order="10230.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_PlanNameDomain" xlink:to="arwr_TwoThousandFourEquityIncentivePlanTwoThousandStockOptionPlanAndInducementGrantsMember" order="10250.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="us-gaap_CommonStockSharesOutstanding" order="10310.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="us-gaap_PreferredStockSharesOutstanding" order="10330.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="us-gaap_DeferredCompensationArrangementWithIndividualCommonStockReservedForFutureIssuance" order="10350.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="arwr_ThresholdPercentageOfCommonStockOwnershipUponPreferredStockConversion" order="10450.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable" xlink:to="us-gaap_RelatedPartyTransactionsByRelatedPartyAxis" order="10020.04" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_RelatedPartyTransactionsByRelatedPartyAxis" xlink:to="us-gaap_RelatedPartyDomain" order="10520.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_RelatedPartyDomain" xlink:to="us-gaap_LimitedLiabilityCompanyMember" order="10540.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="arwr_MaximumEquityCommitmentAmountUnderAgreement" order="10640.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="arwr_EquityCommitmentAgreementPeriod" order="10700.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="arwr_CashDrawnFromFacility" order="10760.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable" xlink:to="us-gaap_StatementScenarioAxis" order="10020.06" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementScenarioAxis" xlink:to="us-gaap_ScenarioUnspecifiedDomain" order="10850.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScenarioUnspecifiedDomain" xlink:to="arwr_SubscriptionAgreementMember" order="10870.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable" xlink:to="us-gaap_StatementClassOfStockAxis" order="10020.08" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementClassOfStockAxis" xlink:to="us-gaap_ClassOfStockDomain" order="10900.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfStockDomain" xlink:to="us-gaap_SeriesAPreferredStockMember" order="10920.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="us-gaap_SaleOfStockPricePerShare" order="11160.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="us-gaap_ProceedsFromIssuanceOfPreferredStockAndPreferenceStock" order="11260.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="us-gaap_StockIssuedDuringPeriodSharesNewIssues" order="11360.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="us-gaap_ConversionOfStockSharesConverted1" order="11460.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="us-gaap_StockIssuedDuringPeriodSharesConversionOfConvertibleSecurities" order="11580.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="arwr_AggregatePurchasePriceOnIssuanceOfCommonStockToBeReceived" order="11870.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="us-gaap_ProceedsFromIssuanceOfCommonStock" order="12230.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="arwr_UnitSoldDescription" order="12290.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="arwr_WarrantToPurchaseShareOfCommonStock" order="12350.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="arwr_CommonStockExercisePrice" order="12410.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="us-gaap_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights" order="13290.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfStockDomain" xlink:to="arwr_ConvertiblePreferredStockSeriesBMember" order="13420.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable" xlink:to="us-gaap_StatementEquityComponentsAxis" order="10020.10" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_StatementEquityComponentsAxis" xlink:to="us-gaap_EquityComponentDomain" order="13450.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_EquityComponentDomain" xlink:to="us-gaap_CommonStockMember" order="13470.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="arwr_ConversionPricePerShare" order="13730.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="us-gaap_ProceedsFromIssuanceOrSaleOfEquity" order="13810.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfStockDomain" xlink:to="us-gaap_SeriesCPreferredStockMember" order="13940.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="arwr_AggregatePriceOnIssuanceOrSaleOfEquity" order="14440.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
  </presentationLink>
  <roleRef roleURI="http://www.arrowheadresearch.com/20140331/taxonomy/role/DisclosureStockholdersEquitySummaryOfInformationAboutWarrantsDetail" xlink:href="arwr-20140331.xsd#Role_DisclosureStockholdersEquitySummaryOfInformationAboutWarrantsDetail" xlink:type="simple" />
  <presentationLink xlink:type="extended" xlink:role="http://www.arrowheadresearch.com/20140331/taxonomy/role/DisclosureStockholdersEquitySummaryOfInformationAboutWarrantsDetail">
    <loc xlink:href="arwr-20140331.xsd#arwr_RemainingLifeOfWarrant" xlink:type="locator" xlink:label="arwr_RemainingLifeOfWarrant" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ClassOfWarrantOrRightOutstanding" xlink:type="locator" xlink:label="us-gaap_ClassOfWarrantOrRightOutstanding" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights" xlink:type="locator" xlink:label="us-gaap_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ClassOfWarrantOrRightLineItems" xlink:type="locator" xlink:label="us-gaap_ClassOfWarrantOrRightLineItems" />
    <loc xlink:href="arwr-20140331.xsd#arwr_WarrantEightMember" xlink:type="locator" xlink:label="arwr_WarrantEightMember" />
    <loc xlink:href="arwr-20140331.xsd#arwr_WarrantSevenMember" xlink:type="locator" xlink:label="arwr_WarrantSevenMember" />
    <loc xlink:href="arwr-20140331.xsd#arwr_WarrantSixMember" xlink:type="locator" xlink:label="arwr_WarrantSixMember" />
    <loc xlink:href="arwr-20140331.xsd#arwr_WarrantFiveMember" xlink:type="locator" xlink:label="arwr_WarrantFiveMember" />
    <loc xlink:href="arwr-20140331.xsd#arwr_WarrantFourMember" xlink:type="locator" xlink:label="arwr_WarrantFourMember" />
    <loc xlink:href="arwr-20140331.xsd#arwr_WarrantThreeMember" xlink:type="locator" xlink:label="arwr_WarrantThreeMember" />
    <loc xlink:href="arwr-20140331.xsd#arwr_WarrantTwoMember" xlink:type="locator" xlink:label="arwr_WarrantTwoMember" />
    <loc xlink:href="arwr-20140331.xsd#arwr_WarrantOneMember" xlink:type="locator" xlink:label="arwr_WarrantOneMember" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ClassOfWarrantOrRightDomain" xlink:type="locator" xlink:label="us-gaap_ClassOfWarrantOrRightDomain" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ClassOfWarrantOrRightAxis" xlink:type="locator" xlink:label="us-gaap_ClassOfWarrantOrRightAxis" />
    <loc xlink:href="http://xbrl.sec.gov/dei/2013/dei-2013-01-31.xsd#dei_EntityDomain" xlink:type="locator" xlink:label="dei_EntityDomain" />
    <loc xlink:href="http://xbrl.sec.gov/dei/2013/dei-2013-01-31.xsd#dei_LegalEntityAxis" xlink:type="locator" xlink:label="dei_LegalEntityAxis" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ClassOfWarrantOrRightTable" xlink:type="locator" xlink:label="us-gaap_ClassOfWarrantOrRightTable" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_EquityAbstract" xlink:type="locator" xlink:label="us-gaap_EquityAbstract" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_EquityAbstract" xlink:to="us-gaap_ClassOfWarrantOrRightTable" order="10010.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfWarrantOrRightTable" xlink:to="dei_LegalEntityAxis" order="10020.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="dei_LegalEntityAxis" xlink:to="dei_EntityDomain" order="10030.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfWarrantOrRightTable" xlink:to="us-gaap_ClassOfWarrantOrRightAxis" order="10020.02" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfWarrantOrRightAxis" xlink:to="us-gaap_ClassOfWarrantOrRightDomain" order="10050.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfWarrantOrRightDomain" xlink:to="arwr_WarrantOneMember" order="10070.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfWarrantOrRightDomain" xlink:to="arwr_WarrantTwoMember" order="10090.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfWarrantOrRightDomain" xlink:to="arwr_WarrantThreeMember" order="10110.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfWarrantOrRightDomain" xlink:to="arwr_WarrantFourMember" order="10130.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfWarrantOrRightDomain" xlink:to="arwr_WarrantFiveMember" order="10150.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfWarrantOrRightDomain" xlink:to="arwr_WarrantSixMember" order="10170.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfWarrantOrRightDomain" xlink:to="arwr_WarrantSevenMember" order="10190.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfWarrantOrRightDomain" xlink:to="arwr_WarrantEightMember" order="10210.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfWarrantOrRightTable" xlink:to="us-gaap_ClassOfWarrantOrRightLineItems" order="10230.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfWarrantOrRightLineItems" xlink:to="us-gaap_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights" order="10270.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfWarrantOrRightLineItems" xlink:to="us-gaap_ClassOfWarrantOrRightOutstanding" order="10630.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfWarrantOrRightLineItems" xlink:to="arwr_RemainingLifeOfWarrant" order="11010.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
  </presentationLink>
  <roleRef roleURI="http://www.arrowheadresearch.com/20140331/taxonomy/role/DisclosureLeasesAdditionalInformationDetail" xlink:href="arwr-20140331.xsd#Role_DisclosureLeasesAdditionalInformationDetail" xlink:type="simple" />
  <presentationLink xlink:type="extended" xlink:role="http://www.arrowheadresearch.com/20140331/taxonomy/role/DisclosureLeasesAdditionalInformationDetail">
    <loc xlink:href="arwr-20140331.xsd#arwr_FacilityAndEquipmentRentExpense" xlink:type="locator" xlink:label="arwr_FacilityAndEquipmentRentExpense" />
    <loc xlink:href="arwr-20140331.xsd#arwr_IncreaseInMonthlyExpenditureDueToUtilitiesCosts" xlink:type="locator" xlink:label="arwr_IncreaseInMonthlyExpenditureDueToUtilitiesCosts" />
    <loc xlink:href="arwr-20140331.xsd#arwr_PaymentsUnderCapitalLease" xlink:type="locator" xlink:label="arwr_PaymentsUnderCapitalLease" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_UtilitiesCosts" xlink:type="locator" xlink:label="us-gaap_UtilitiesCosts" />
    <loc xlink:href="arwr-20140331.xsd#arwr_OtherRentalExpenses" xlink:type="locator" xlink:label="arwr_OtherRentalExpenses" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_AssetsHeldUnderCapitalLeasesMember" xlink:type="locator" xlink:label="us-gaap_AssetsHeldUnderCapitalLeasesMember" />
    <loc xlink:href="arwr-20140331.xsd#arwr_ResearchFacilityInMadisonMember" xlink:type="locator" xlink:label="arwr_ResearchFacilityInMadisonMember" />
    <loc xlink:href="arwr-20140331.xsd#arwr_PercentageOfIncreaseInAnnualRentalCost" xlink:type="locator" xlink:label="arwr_PercentageOfIncreaseInAnnualRentalCost" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_LeaseAndRentalExpense" xlink:type="locator" xlink:label="us-gaap_LeaseAndRentalExpense" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_LeaseExpirationDate1" xlink:type="locator" xlink:label="us-gaap_LeaseExpirationDate1" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ComponentOfOperatingOtherCostAndExpenseLineItems" xlink:type="locator" xlink:label="us-gaap_ComponentOfOperatingOtherCostAndExpenseLineItems" />
    <loc xlink:href="arwr-20140331.xsd#arwr_CorporateHeadquartersInPasadenaMember" xlink:type="locator" xlink:label="arwr_CorporateHeadquartersInPasadenaMember" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_PropertySubjectToOrAvailableForOperatingLeaseDomain" xlink:type="locator" xlink:label="us-gaap_PropertySubjectToOrAvailableForOperatingLeaseDomain" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_PropertySubjectToOrAvailableForOperatingLeaseAxis" xlink:type="locator" xlink:label="us-gaap_PropertySubjectToOrAvailableForOperatingLeaseAxis" />
    <loc xlink:href="http://xbrl.sec.gov/dei/2013/dei-2013-01-31.xsd#dei_EntityDomain" xlink:type="locator" xlink:label="dei_EntityDomain" />
    <loc xlink:href="http://xbrl.sec.gov/dei/2013/dei-2013-01-31.xsd#dei_LegalEntityAxis" xlink:type="locator" xlink:label="dei_LegalEntityAxis" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ScheduleOfOperatingLeasedAssetsTable" xlink:type="locator" xlink:label="us-gaap_ScheduleOfOperatingLeasedAssetsTable" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_BusinessCombinationsAbstract" xlink:type="locator" xlink:label="us-gaap_BusinessCombinationsAbstract" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_BusinessCombinationsAbstract" xlink:to="us-gaap_ScheduleOfOperatingLeasedAssetsTable" order="10010.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfOperatingLeasedAssetsTable" xlink:to="dei_LegalEntityAxis" order="10020.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="dei_LegalEntityAxis" xlink:to="dei_EntityDomain" order="10030.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfOperatingLeasedAssetsTable" xlink:to="us-gaap_PropertySubjectToOrAvailableForOperatingLeaseAxis" order="10020.02" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_PropertySubjectToOrAvailableForOperatingLeaseAxis" xlink:to="us-gaap_PropertySubjectToOrAvailableForOperatingLeaseDomain" order="10050.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_PropertySubjectToOrAvailableForOperatingLeaseDomain" xlink:to="arwr_CorporateHeadquartersInPasadenaMember" order="10070.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfOperatingLeasedAssetsTable" xlink:to="us-gaap_ComponentOfOperatingOtherCostAndExpenseLineItems" order="10130.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ComponentOfOperatingOtherCostAndExpenseLineItems" xlink:to="us-gaap_LeaseExpirationDate1" order="10170.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ComponentOfOperatingOtherCostAndExpenseLineItems" xlink:to="us-gaap_LeaseAndRentalExpense" order="10210.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ComponentOfOperatingOtherCostAndExpenseLineItems" xlink:to="arwr_PercentageOfIncreaseInAnnualRentalCost" order="10250.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_PropertySubjectToOrAvailableForOperatingLeaseDomain" xlink:to="arwr_ResearchFacilityInMadisonMember" order="10340.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_PropertySubjectToOrAvailableForOperatingLeaseDomain" xlink:to="us-gaap_AssetsHeldUnderCapitalLeasesMember" order="10380.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ComponentOfOperatingOtherCostAndExpenseLineItems" xlink:to="arwr_OtherRentalExpenses" order="10520.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ComponentOfOperatingOtherCostAndExpenseLineItems" xlink:to="us-gaap_UtilitiesCosts" order="10560.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ComponentOfOperatingOtherCostAndExpenseLineItems" xlink:to="arwr_PaymentsUnderCapitalLease" order="10600.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ComponentOfOperatingOtherCostAndExpenseLineItems" xlink:to="arwr_IncreaseInMonthlyExpenditureDueToUtilitiesCosts" order="10640.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ComponentOfOperatingOtherCostAndExpenseLineItems" xlink:to="arwr_FacilityAndEquipmentRentExpense" order="10740.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
  </presentationLink>
  <roleRef roleURI="http://www.arrowheadresearch.com/20140331/taxonomy/role/DisclosureLeasesFutureMinimumLeasePaymentsUnderCapitalizedLeasesDetail" xlink:href="arwr-20140331.xsd#Role_DisclosureLeasesFutureMinimumLeasePaymentsUnderCapitalizedLeasesDetail" xlink:type="simple" />
  <presentationLink xlink:type="extended" xlink:role="http://www.arrowheadresearch.com/20140331/taxonomy/role/DisclosureLeasesFutureMinimumLeasePaymentsUnderCapitalizedLeasesDetail">
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_CapitalLeaseObligationsNoncurrent" xlink:type="locator" xlink:label="us-gaap_CapitalLeaseObligationsNoncurrent" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_CapitalLeaseObligationsCurrent" xlink:type="locator" xlink:label="us-gaap_CapitalLeaseObligationsCurrent" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_CapitalLeasesFutureMinimumPaymentsPresentValueOfNetMinimumPayments" xlink:type="locator" xlink:label="us-gaap_CapitalLeasesFutureMinimumPaymentsPresentValueOfNetMinimumPayments" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_CapitalLeasesFutureMinimumPaymentsInterestIncludedInPayments" xlink:type="locator" xlink:label="us-gaap_CapitalLeasesFutureMinimumPaymentsInterestIncludedInPayments" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_CapitalLeasesFutureMinimumPaymentsDueThereafter" xlink:type="locator" xlink:label="us-gaap_CapitalLeasesFutureMinimumPaymentsDueThereafter" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_CapitalLeasesFutureMinimumPaymentsDueInFiveYears" xlink:type="locator" xlink:label="us-gaap_CapitalLeasesFutureMinimumPaymentsDueInFiveYears" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_CapitalLeasesFutureMinimumPaymentsDueInFourYears" xlink:type="locator" xlink:label="us-gaap_CapitalLeasesFutureMinimumPaymentsDueInFourYears" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_CapitalLeasesFutureMinimumPaymentsDueInThreeYears" xlink:type="locator" xlink:label="us-gaap_CapitalLeasesFutureMinimumPaymentsDueInThreeYears" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_CapitalLeasesFutureMinimumPaymentsDueInTwoYears" xlink:type="locator" xlink:label="us-gaap_CapitalLeasesFutureMinimumPaymentsDueInTwoYears" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_CapitalLeasesFutureMinimumPaymentsDueCurrent" xlink:type="locator" xlink:label="us-gaap_CapitalLeasesFutureMinimumPaymentsDueCurrent" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_CapitalLeasedAssetsLineItems" xlink:type="locator" xlink:label="us-gaap_CapitalLeasedAssetsLineItems" />
    <loc xlink:href="http://xbrl.sec.gov/dei/2013/dei-2013-01-31.xsd#dei_EntityDomain" xlink:type="locator" xlink:label="dei_EntityDomain" />
    <loc xlink:href="http://xbrl.sec.gov/dei/2013/dei-2013-01-31.xsd#dei_LegalEntityAxis" xlink:type="locator" xlink:label="dei_LegalEntityAxis" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ScheduleOfCapitalLeasedAsssetsTable" xlink:type="locator" xlink:label="us-gaap_ScheduleOfCapitalLeasedAsssetsTable" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_LeasesAbstract" xlink:type="locator" xlink:label="us-gaap_LeasesAbstract" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_LeasesAbstract" xlink:to="us-gaap_ScheduleOfCapitalLeasedAsssetsTable" order="10080.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfCapitalLeasedAsssetsTable" xlink:to="dei_LegalEntityAxis" order="10090.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="dei_LegalEntityAxis" xlink:to="dei_EntityDomain" order="10100.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfCapitalLeasedAsssetsTable" xlink:to="us-gaap_CapitalLeasedAssetsLineItems" order="10110.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_CapitalLeasedAssetsLineItems" xlink:to="us-gaap_CapitalLeasesFutureMinimumPaymentsDueCurrent" order="10150.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_CapitalLeasedAssetsLineItems" xlink:to="us-gaap_CapitalLeasesFutureMinimumPaymentsDueInTwoYears" order="10190.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_CapitalLeasedAssetsLineItems" xlink:to="us-gaap_CapitalLeasesFutureMinimumPaymentsDueInThreeYears" order="10230.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_CapitalLeasedAssetsLineItems" xlink:to="us-gaap_CapitalLeasesFutureMinimumPaymentsDueInFourYears" order="10270.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_CapitalLeasedAssetsLineItems" xlink:to="us-gaap_CapitalLeasesFutureMinimumPaymentsDueInFiveYears" order="10310.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_CapitalLeasedAssetsLineItems" xlink:to="us-gaap_CapitalLeasesFutureMinimumPaymentsDueThereafter" order="10350.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_CapitalLeasedAssetsLineItems" xlink:to="us-gaap_CapitalLeasesFutureMinimumPaymentsInterestIncludedInPayments" order="10390.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2009/role/negatedLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_CapitalLeasedAssetsLineItems" xlink:to="us-gaap_CapitalLeasesFutureMinimumPaymentsPresentValueOfNetMinimumPayments" order="10430.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/totalLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_CapitalLeasedAssetsLineItems" xlink:to="us-gaap_CapitalLeaseObligationsCurrent" order="10470.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2009/role/negatedLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_CapitalLeasedAssetsLineItems" xlink:to="us-gaap_CapitalLeaseObligationsNoncurrent" order="10490.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
  </presentationLink>
  <roleRef roleURI="http://www.arrowheadresearch.com/20140331/taxonomy/role/DisclosureLeasesFutureMinimumLeasePaymentsUnderOperatingLeasesDetail" xlink:href="arwr-20140331.xsd#Role_DisclosureLeasesFutureMinimumLeasePaymentsUnderOperatingLeasesDetail" xlink:type="simple" />
  <presentationLink xlink:type="extended" xlink:role="http://www.arrowheadresearch.com/20140331/taxonomy/role/DisclosureLeasesFutureMinimumLeasePaymentsUnderOperatingLeasesDetail">
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_OperatingLeasesFutureMinimumPaymentsDue" xlink:type="locator" xlink:label="us-gaap_OperatingLeasesFutureMinimumPaymentsDue" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_OperatingLeasesFutureMinimumPaymentsDueThereafter" xlink:type="locator" xlink:label="us-gaap_OperatingLeasesFutureMinimumPaymentsDueThereafter" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_OperatingLeasesFutureMinimumPaymentsDueInFiveYears" xlink:type="locator" xlink:label="us-gaap_OperatingLeasesFutureMinimumPaymentsDueInFiveYears" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_OperatingLeasesFutureMinimumPaymentsDueInFourYears" xlink:type="locator" xlink:label="us-gaap_OperatingLeasesFutureMinimumPaymentsDueInFourYears" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_OperatingLeasesFutureMinimumPaymentsDueInThreeYears" xlink:type="locator" xlink:label="us-gaap_OperatingLeasesFutureMinimumPaymentsDueInThreeYears" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_OperatingLeasesFutureMinimumPaymentsDueInTwoYears" xlink:type="locator" xlink:label="us-gaap_OperatingLeasesFutureMinimumPaymentsDueInTwoYears" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_OperatingLeasesFutureMinimumPaymentsDueCurrent" xlink:type="locator" xlink:label="us-gaap_OperatingLeasesFutureMinimumPaymentsDueCurrent" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_OperatingLeasedAssetsLineItems" xlink:type="locator" xlink:label="us-gaap_OperatingLeasedAssetsLineItems" />
    <loc xlink:href="http://xbrl.sec.gov/dei/2013/dei-2013-01-31.xsd#dei_EntityDomain" xlink:type="locator" xlink:label="dei_EntityDomain" />
    <loc xlink:href="http://xbrl.sec.gov/dei/2013/dei-2013-01-31.xsd#dei_LegalEntityAxis" xlink:type="locator" xlink:label="dei_LegalEntityAxis" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ScheduleOfOperatingLeasedAssetsTable" xlink:type="locator" xlink:label="us-gaap_ScheduleOfOperatingLeasedAssetsTable" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_LeasesAbstract" xlink:type="locator" xlink:label="us-gaap_LeasesAbstract" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_LeasesAbstract" xlink:to="us-gaap_ScheduleOfOperatingLeasedAssetsTable" order="10070.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfOperatingLeasedAssetsTable" xlink:to="dei_LegalEntityAxis" order="10080.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="dei_LegalEntityAxis" xlink:to="dei_EntityDomain" order="10090.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfOperatingLeasedAssetsTable" xlink:to="us-gaap_OperatingLeasedAssetsLineItems" order="10100.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_OperatingLeasedAssetsLineItems" xlink:to="us-gaap_OperatingLeasesFutureMinimumPaymentsDueCurrent" order="10140.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_OperatingLeasedAssetsLineItems" xlink:to="us-gaap_OperatingLeasesFutureMinimumPaymentsDueInTwoYears" order="10180.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_OperatingLeasedAssetsLineItems" xlink:to="us-gaap_OperatingLeasesFutureMinimumPaymentsDueInThreeYears" order="10220.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_OperatingLeasedAssetsLineItems" xlink:to="us-gaap_OperatingLeasesFutureMinimumPaymentsDueInFourYears" order="10260.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_OperatingLeasedAssetsLineItems" xlink:to="us-gaap_OperatingLeasesFutureMinimumPaymentsDueInFiveYears" order="10300.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_OperatingLeasedAssetsLineItems" xlink:to="us-gaap_OperatingLeasesFutureMinimumPaymentsDueThereafter" order="10340.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_OperatingLeasedAssetsLineItems" xlink:to="us-gaap_OperatingLeasesFutureMinimumPaymentsDue" order="10380.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/totalLabel" />
  </presentationLink>
  <roleRef roleURI="http://www.arrowheadresearch.com/20140331/taxonomy/role/DisclosureStockBasedCompensationAdditionalInformationDetail" xlink:href="arwr-20140331.xsd#Role_DisclosureStockBasedCompensationAdditionalInformationDetail" xlink:type="simple" />
  <presentationLink xlink:type="extended" xlink:role="http://www.arrowheadresearch.com/20140331/taxonomy/role/DisclosureStockBasedCompensationAdditionalInformationDetail">
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber" xlink:type="locator" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_RestrictedStockUnitsRSUMember" xlink:type="locator" xlink:label="us-gaap_RestrictedStockUnitsRSUMember" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" xlink:type="locator" xlink:label="us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_AwardTypeAxis" xlink:type="locator" xlink:label="us-gaap_AwardTypeAxis" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedDividendRate" xlink:type="locator" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedDividendRate" />
    <loc xlink:href="arwr-20140331.xsd#arwr_WeightedAveragePeriodToRecognizePreTaxCompensationExpense" xlink:type="locator" xlink:label="arwr_WeightedAveragePeriodToRecognizePreTaxCompensationExpense" />
    <loc xlink:href="arwr-20140331.xsd#arwr_PreTaxCompensationExpense" xlink:type="locator" xlink:label="arwr_PreTaxCompensationExpense" />
    <loc xlink:href="arwr-20140331.xsd#arwr_ArrowheadMember" xlink:type="locator" xlink:label="arwr_ArrowheadMember" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisesInPeriodTotalIntrinsicValue" xlink:type="locator" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisesInPeriodTotalIntrinsicValue" />
    <loc xlink:href="arwr-20140331.xsd#arwr_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodFairValue" xlink:type="locator" xlink:label="arwr_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodFairValue" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_RelatedPartyDomain" xlink:type="locator" xlink:label="us-gaap_RelatedPartyDomain" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_RelatedPartyTransactionsByRelatedPartyAxis" xlink:type="locator" xlink:label="us-gaap_RelatedPartyTransactionsByRelatedPartyAxis" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_AllocatedShareBasedCompensationExpense" xlink:type="locator" xlink:label="us-gaap_AllocatedShareBasedCompensationExpense" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsGranted" xlink:type="locator" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsGranted" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross" xlink:type="locator" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber" xlink:type="locator" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_CommonStockCapitalSharesReservedForFutureIssuance" xlink:type="locator" xlink:label="us-gaap_CommonStockCapitalSharesReservedForFutureIssuance" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:type="locator" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" />
    <loc xlink:href="arwr-20140331.xsd#arwr_TwoThousandsThirteenIncentivePlanMember" xlink:type="locator" xlink:label="arwr_TwoThousandsThirteenIncentivePlanMember" />
    <loc xlink:href="arwr-20140331.xsd#arwr_TwoThousandsFourEquityIncentivePlanMember" xlink:type="locator" xlink:label="arwr_TwoThousandsFourEquityIncentivePlanMember" />
    <loc xlink:href="arwr-20140331.xsd#arwr_TwoThousandsStockOptionPlanMember" xlink:type="locator" xlink:label="arwr_TwoThousandsStockOptionPlanMember" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_PlanNameDomain" xlink:type="locator" xlink:label="us-gaap_PlanNameDomain" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_PlanNameAxis" xlink:type="locator" xlink:label="us-gaap_PlanNameAxis" />
    <loc xlink:href="http://xbrl.sec.gov/dei/2013/dei-2013-01-31.xsd#dei_EntityDomain" xlink:type="locator" xlink:label="dei_EntityDomain" />
    <loc xlink:href="http://xbrl.sec.gov/dei/2013/dei-2013-01-31.xsd#dei_LegalEntityAxis" xlink:type="locator" xlink:label="dei_LegalEntityAxis" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable" xlink:type="locator" xlink:label="us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DisclosureOfCompensationRelatedCostsSharebasedPaymentsAbstract" xlink:type="locator" xlink:label="us-gaap_DisclosureOfCompensationRelatedCostsSharebasedPaymentsAbstract" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DisclosureOfCompensationRelatedCostsSharebasedPaymentsAbstract" xlink:to="us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable" order="10010.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable" xlink:to="dei_LegalEntityAxis" order="10020.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="dei_LegalEntityAxis" xlink:to="dei_EntityDomain" order="10030.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable" xlink:to="us-gaap_PlanNameAxis" order="10020.02" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_PlanNameAxis" xlink:to="us-gaap_PlanNameDomain" order="10050.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_PlanNameDomain" xlink:to="arwr_TwoThousandsStockOptionPlanMember" order="10070.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_PlanNameDomain" xlink:to="arwr_TwoThousandsFourEquityIncentivePlanMember" order="10090.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_PlanNameDomain" xlink:to="arwr_TwoThousandsThirteenIncentivePlanMember" order="10110.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" order="10170.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="us-gaap_CommonStockCapitalSharesReservedForFutureIssuance" order="10210.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber" order="10450.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross" order="10670.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNonOptionEquityInstrumentsGranted" order="10870.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="us-gaap_AllocatedShareBasedCompensationExpense" order="11110.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable" xlink:to="us-gaap_RelatedPartyTransactionsByRelatedPartyAxis" order="10020.04" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_RelatedPartyTransactionsByRelatedPartyAxis" xlink:to="us-gaap_RelatedPartyDomain" order="11220.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="arwr_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodFairValue" order="11280.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisesInPeriodTotalIntrinsicValue" order="11420.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_RelatedPartyDomain" xlink:to="arwr_ArrowheadMember" order="11550.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="arwr_PreTaxCompensationExpense" order="11630.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="arwr_WeightedAveragePeriodToRecognizePreTaxCompensationExpense" order="11690.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedDividendRate" order="11810.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable" xlink:to="us-gaap_AwardTypeAxis" order="10020.06" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AwardTypeAxis" xlink:to="us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" order="11860.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" xlink:to="us-gaap_RestrictedStockUnitsRSUMember" order="11880.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber" order="11940.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
  </presentationLink>
  <roleRef roleURI="http://www.arrowheadresearch.com/20140331/taxonomy/role/DisclosureStockBasedCompensationSummarizeInformationAboutStockOptionsDetail" xlink:href="arwr-20140331.xsd#Role_DisclosureStockBasedCompensationSummarizeInformationAboutStockOptionsDetail" xlink:type="simple" />
  <presentationLink xlink:type="extended" xlink:role="http://www.arrowheadresearch.com/20140331/taxonomy/role/DisclosureStockBasedCompensationSummarizeInformationAboutStockOptionsDetail">
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableIntrinsicValue1" xlink:type="locator" xlink:label="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableIntrinsicValue1" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingIntrinsicValue" xlink:type="locator" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingIntrinsicValue" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableWeightedAverageRemainingContractualTerm1" xlink:type="locator" xlink:label="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableWeightedAverageRemainingContractualTerm1" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsOutstandingWeightedAverageRemainingContractualTerm2" xlink:type="locator" xlink:label="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsOutstandingWeightedAverageRemainingContractualTerm2" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableWeightedAverageExercisePrice" xlink:type="locator" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableWeightedAverageExercisePrice" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice" xlink:type="locator" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice_li0l2" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsExercisesInPeriodWeightedAverageExercisePrice" xlink:type="locator" xlink:label="us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsExercisesInPeriodWeightedAverageExercisePrice" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsExpirationsInPeriodWeightedAverageExercisePrice" xlink:type="locator" xlink:label="us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsExpirationsInPeriodWeightedAverageExercisePrice" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageExercisePrice" xlink:type="locator" xlink:label="us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageExercisePrice" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice" xlink:type="locator" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableNumber" xlink:type="locator" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableNumber" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber" xlink:type="locator" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber_li0l2" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised" xlink:type="locator" xlink:label="us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExpirationsInPeriod" xlink:type="locator" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExpirationsInPeriod" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross" xlink:type="locator" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber" xlink:type="locator" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:type="locator" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" />
    <loc xlink:href="http://xbrl.sec.gov/dei/2013/dei-2013-01-31.xsd#dei_EntityDomain" xlink:type="locator" xlink:label="dei_EntityDomain" />
    <loc xlink:href="http://xbrl.sec.gov/dei/2013/dei-2013-01-31.xsd#dei_LegalEntityAxis" xlink:type="locator" xlink:label="dei_LegalEntityAxis" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable" xlink:type="locator" xlink:label="us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DisclosureOfCompensationRelatedCostsSharebasedPaymentsAbstract" xlink:type="locator" xlink:label="us-gaap_DisclosureOfCompensationRelatedCostsSharebasedPaymentsAbstract" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DisclosureOfCompensationRelatedCostsSharebasedPaymentsAbstract" xlink:to="us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable" order="10010.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable" xlink:to="dei_LegalEntityAxis" order="10020.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="dei_LegalEntityAxis" xlink:to="dei_EntityDomain" order="10030.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" order="10040.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber" order="10080.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/periodStartLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross" order="10200.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExpirationsInPeriod" order="10320.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2009/role/negatedLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised" order="10440.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2009/role/negatedLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber_li0l2" order="10560.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/periodEndLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableNumber" order="11640.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice" order="11820.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/periodStartLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageExercisePrice" order="11940.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsExpirationsInPeriodWeightedAverageExercisePrice" order="12060.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsExercisesInPeriodWeightedAverageExercisePrice" order="12180.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice_li0l2" order="12300.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/periodEndLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableWeightedAverageExercisePrice" order="13380.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsOutstandingWeightedAverageRemainingContractualTerm2" order="13560.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableWeightedAverageRemainingContractualTerm1" order="13680.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingIntrinsicValue" order="13860.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableIntrinsicValue1" order="13980.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
  </presentationLink>
  <roleRef roleURI="http://www.arrowheadresearch.com/20140331/taxonomy/role/DisclosureStockBasedCompensationAssumptionsUsedToValueStockOptionsDetail" xlink:href="arwr-20140331.xsd#Role_DisclosureStockBasedCompensationAssumptionsUsedToValueStockOptionsDetail" xlink:type="simple" />
  <presentationLink xlink:type="extended" xlink:role="http://www.arrowheadresearch.com/20140331/taxonomy/role/DisclosureStockBasedCompensationAssumptionsUsedToValueStockOptionsDetail">
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageGrantDateFairValue" xlink:type="locator" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageGrantDateFairValue" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardFairValueAssumptionsExpectedTerm1" xlink:type="locator" xlink:label="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardFairValueAssumptionsExpectedTerm1" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRate" xlink:type="locator" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRate" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate" xlink:type="locator" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRateMaximum" xlink:type="locator" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRateMaximum" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRateMinimum" xlink:type="locator" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRateMinimum" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedDividendRate" xlink:type="locator" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedDividendRate" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:type="locator" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_MaximumMember" xlink:type="locator" xlink:label="us-gaap_MaximumMember" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_MinimumMember" xlink:type="locator" xlink:label="us-gaap_MinimumMember" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_RangeMember" xlink:type="locator" xlink:label="us-gaap_RangeMember" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_RangeAxis" xlink:type="locator" xlink:label="us-gaap_RangeAxis" />
    <loc xlink:href="http://xbrl.sec.gov/dei/2013/dei-2013-01-31.xsd#dei_EntityDomain" xlink:type="locator" xlink:label="dei_EntityDomain" />
    <loc xlink:href="http://xbrl.sec.gov/dei/2013/dei-2013-01-31.xsd#dei_LegalEntityAxis" xlink:type="locator" xlink:label="dei_LegalEntityAxis" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable" xlink:type="locator" xlink:label="us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DisclosureOfCompensationRelatedCostsSharebasedPaymentsAbstract" xlink:type="locator" xlink:label="us-gaap_DisclosureOfCompensationRelatedCostsSharebasedPaymentsAbstract" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DisclosureOfCompensationRelatedCostsSharebasedPaymentsAbstract" xlink:to="us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable" order="10010.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable" xlink:to="dei_LegalEntityAxis" order="10020.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="dei_LegalEntityAxis" xlink:to="dei_EntityDomain" order="10030.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable" xlink:to="us-gaap_RangeAxis" order="10020.02" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_RangeAxis" xlink:to="us-gaap_RangeMember" order="10050.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_RangeMember" xlink:to="us-gaap_MinimumMember" order="10070.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_RangeMember" xlink:to="us-gaap_MaximumMember" order="10090.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" order="10150.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedDividendRate" order="10190.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRateMinimum" order="10350.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRateMaximum" order="10510.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate" order="10670.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRate" order="10890.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardFairValueAssumptionsExpectedTerm1" order="11050.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageGrantDateFairValue" order="11250.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
  </presentationLink>
  <roleRef roleURI="http://www.arrowheadresearch.com/20140331/taxonomy/role/DisclosureStockBasedCompensationSummaryOfRestrictedStockActivityDetail" xlink:href="arwr-20140331.xsd#Role_DisclosureStockBasedCompensationSummaryOfRestrictedStockActivityDetail" xlink:type="simple" />
  <presentationLink xlink:type="extended" xlink:role="http://www.arrowheadresearch.com/20140331/taxonomy/role/DisclosureStockBasedCompensationSummaryOfRestrictedStockActivityDetail">
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue" xlink:type="locator" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue_li0l2" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeituresWeightedAverageGrantDateFairValue" xlink:type="locator" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeituresWeightedAverageGrantDateFairValue" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue" xlink:type="locator" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue" xlink:type="locator" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue" xlink:type="locator" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber" xlink:type="locator" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber_li0l2" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod" xlink:type="locator" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod" xlink:type="locator" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod" xlink:type="locator" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber" xlink:type="locator" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:type="locator" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_RestrictedStockUnitsRSUMember" xlink:type="locator" xlink:label="us-gaap_RestrictedStockUnitsRSUMember" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" xlink:type="locator" xlink:label="us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_AwardTypeAxis" xlink:type="locator" xlink:label="us-gaap_AwardTypeAxis" />
    <loc xlink:href="http://xbrl.sec.gov/dei/2013/dei-2013-01-31.xsd#dei_EntityDomain" xlink:type="locator" xlink:label="dei_EntityDomain" />
    <loc xlink:href="http://xbrl.sec.gov/dei/2013/dei-2013-01-31.xsd#dei_LegalEntityAxis" xlink:type="locator" xlink:label="dei_LegalEntityAxis" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable" xlink:type="locator" xlink:label="us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DisclosureOfCompensationRelatedCostsSharebasedPaymentsAbstract" xlink:type="locator" xlink:label="us-gaap_DisclosureOfCompensationRelatedCostsSharebasedPaymentsAbstract" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_DisclosureOfCompensationRelatedCostsSharebasedPaymentsAbstract" xlink:to="us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable" order="10010.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable" xlink:to="dei_LegalEntityAxis" order="10020.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="dei_LegalEntityAxis" xlink:to="dei_EntityDomain" order="10030.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable" xlink:to="us-gaap_AwardTypeAxis" order="10020.02" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_AwardTypeAxis" xlink:to="us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" order="10050.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" xlink:to="us-gaap_RestrictedStockUnitsRSUMember" order="10070.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" order="10090.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber" order="10130.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/periodStartLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod" order="10210.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod" order="10290.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod" order="10370.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber_li0l2" order="10450.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/periodEndLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue" order="10620.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/periodStartLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue" order="10700.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue" order="10780.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeituresWeightedAverageGrantDateFairValue" order="10860.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue_li0l2" order="10940.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/periodEndLabel" />
  </presentationLink>
  <roleRef roleURI="http://www.arrowheadresearch.com/20140331/taxonomy/role/DisclosureFairValueMeasurementsFairValueMeasurementsForAssetsAndLiabilitiesMeasuredAtFairValueOnRecurringBasisDetail" xlink:href="arwr-20140331.xsd#Role_DisclosureFairValueMeasurementsFairValueMeasurementsForAssetsAndLiabilitiesMeasuredAtFairValueOnRecurringBasisDetail" xlink:type="simple" />
  <presentationLink xlink:type="extended" xlink:role="http://www.arrowheadresearch.com/20140331/taxonomy/role/DisclosureFairValueMeasurementsFairValueMeasurementsForAssetsAndLiabilitiesMeasuredAtFairValueOnRecurringBasisDetail">
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_BusinessCombinationContingentConsiderationLiability" xlink:type="locator" xlink:label="us-gaap_BusinessCombinationContingentConsiderationLiability" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DerivativeLiabilities" xlink:type="locator" xlink:label="us-gaap_DerivativeLiabilities" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DerivativeAssetsNoncurrent" xlink:type="locator" xlink:label="us-gaap_DerivativeAssetsNoncurrent" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_CashAndCashEquivalentsFairValueDisclosure" xlink:type="locator" xlink:label="us-gaap_CashAndCashEquivalentsFairValueDisclosure" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems" xlink:type="locator" xlink:label="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_FairValueInputsLevel3Member" xlink:type="locator" xlink:label="us-gaap_FairValueInputsLevel3Member" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_FairValueInputsLevel2Member" xlink:type="locator" xlink:label="us-gaap_FairValueInputsLevel2Member" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_FairValueInputsLevel1Member" xlink:type="locator" xlink:label="us-gaap_FairValueInputsLevel1Member" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain" xlink:type="locator" xlink:label="us-gaap_FairValueMeasurementsFairValueHierarchyDomain" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_FairValueByFairValueHierarchyLevelAxis" xlink:type="locator" xlink:label="us-gaap_FairValueByFairValueHierarchyLevelAxis" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_FairValueMeasurementsRecurringMember" xlink:type="locator" xlink:label="us-gaap_FairValueMeasurementsRecurringMember" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_FairValueMeasurementFrequencyDomain" xlink:type="locator" xlink:label="us-gaap_FairValueMeasurementFrequencyDomain" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_FairValueByMeasurementFrequencyAxis" xlink:type="locator" xlink:label="us-gaap_FairValueByMeasurementFrequencyAxis" />
    <loc xlink:href="http://xbrl.sec.gov/dei/2013/dei-2013-01-31.xsd#dei_EntityDomain" xlink:type="locator" xlink:label="dei_EntityDomain" />
    <loc xlink:href="http://xbrl.sec.gov/dei/2013/dei-2013-01-31.xsd#dei_LegalEntityAxis" xlink:type="locator" xlink:label="dei_LegalEntityAxis" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable" xlink:type="locator" xlink:label="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_FairValueDisclosuresAbstract" xlink:type="locator" xlink:label="us-gaap_FairValueDisclosuresAbstract" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueDisclosuresAbstract" xlink:to="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable" order="10010.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable" xlink:to="dei_LegalEntityAxis" order="10020.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="dei_LegalEntityAxis" xlink:to="dei_EntityDomain" order="10030.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable" xlink:to="us-gaap_FairValueByMeasurementFrequencyAxis" order="10020.02" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueByMeasurementFrequencyAxis" xlink:to="us-gaap_FairValueMeasurementFrequencyDomain" order="10050.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueMeasurementFrequencyDomain" xlink:to="us-gaap_FairValueMeasurementsRecurringMember" order="10070.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable" xlink:to="us-gaap_FairValueByFairValueHierarchyLevelAxis" order="10020.04" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueByFairValueHierarchyLevelAxis" xlink:to="us-gaap_FairValueMeasurementsFairValueHierarchyDomain" order="10160.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueMeasurementsFairValueHierarchyDomain" xlink:to="us-gaap_FairValueInputsLevel1Member" order="10180.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueMeasurementsFairValueHierarchyDomain" xlink:to="us-gaap_FairValueInputsLevel2Member" order="10200.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueMeasurementsFairValueHierarchyDomain" xlink:to="us-gaap_FairValueInputsLevel3Member" order="10220.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable" xlink:to="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems" order="10240.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems" xlink:to="us-gaap_CashAndCashEquivalentsFairValueDisclosure" order="10280.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems" xlink:to="us-gaap_DerivativeAssetsNoncurrent" order="10400.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems" xlink:to="us-gaap_DerivativeLiabilities" order="10560.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems" xlink:to="us-gaap_BusinessCombinationContingentConsiderationLiability" order="10680.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
  </presentationLink>
  <roleRef roleURI="http://www.arrowheadresearch.com/20140331/taxonomy/role/DisclosureFairValueMeasurementsAdditionalInformationDetail" xlink:href="arwr-20140331.xsd#Role_DisclosureFairValueMeasurementsAdditionalInformationDetail" xlink:type="simple" />
  <presentationLink xlink:type="extended" xlink:role="http://www.arrowheadresearch.com/20140331/taxonomy/role/DisclosureFairValueMeasurementsAdditionalInformationDetail">
    <loc xlink:href="arwr-20140331.xsd#arwr_NumberOfExchangeRightAreSold" xlink:type="locator" xlink:label="arwr_NumberOfExchangeRightAreSold" />
    <loc xlink:href="arwr-20140331.xsd#arwr_ExchangeRightConvertibleConversionRatioForFiveYear" xlink:type="locator" xlink:label="arwr_ExchangeRightConvertibleConversionRatioForFiveYear" />
    <loc xlink:href="arwr-20140331.xsd#arwr_ExchangeRightConvertibleConversionRatioForFourYear" xlink:type="locator" xlink:label="arwr_ExchangeRightConvertibleConversionRatioForFourYear" />
    <loc xlink:href="arwr-20140331.xsd#arwr_ExchangeRightConvertibleConversionRatioForThreeYear" xlink:type="locator" xlink:label="arwr_ExchangeRightConvertibleConversionRatioForThreeYear" />
    <loc xlink:href="arwr-20140331.xsd#arwr_ExchangeRightConvertibleConversionRatioForTwoYear" xlink:type="locator" xlink:label="arwr_ExchangeRightConvertibleConversionRatioForTwoYear" />
    <loc xlink:href="arwr-20140331.xsd#arwr_ExchangeRightConvertibleConversionRatioForFirstYear" xlink:type="locator" xlink:label="arwr_ExchangeRightConvertibleConversionRatioForFirstYear" />
    <loc xlink:href="arwr-20140331.xsd#arwr_TermOfExchangeRights" xlink:type="locator" xlink:label="arwr_TermOfExchangeRights" />
    <loc xlink:href="arwr-20140331.xsd#arwr_AblarisTherapeuticsMember" xlink:type="locator" xlink:label="arwr_AblarisTherapeuticsMember" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilityGainLossIncludedInEarnings" xlink:type="locator" xlink:label="us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilityGainLossIncludedInEarnings" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ClassOfWarrantOrRightOutstanding" xlink:type="locator" xlink:label="us-gaap_ClassOfWarrantOrRightOutstanding" />
    <loc xlink:href="arwr-20140331.xsd#arwr_WarrantsIssuedToAcquireCommonStock" xlink:type="locator" xlink:label="arwr_WarrantsIssuedToAcquireCommonStock" />
    <loc xlink:href="arwr-20140331.xsd#arwr_TwoThousandThirteenWarrantsMember" xlink:type="locator" xlink:label="arwr_TwoThousandThirteenWarrantsMember" />
    <loc xlink:href="arwr-20140331.xsd#arwr_TwoThousandsTwelveWarrantsMember" xlink:type="locator" xlink:label="arwr_TwoThousandsTwelveWarrantsMember" />
    <loc xlink:href="arwr-20140331.xsd#arwr_TwoThousandTenWarrantsMember" xlink:type="locator" xlink:label="arwr_TwoThousandTenWarrantsMember" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ClassOfWarrantOrRightDomain" xlink:type="locator" xlink:label="us-gaap_ClassOfWarrantOrRightDomain" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ClassOfWarrantOrRightAxis" xlink:type="locator" xlink:label="us-gaap_ClassOfWarrantOrRightAxis" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DebtInstrumentConvertibleConversionPrice1" xlink:type="locator" xlink:label="us-gaap_DebtInstrumentConvertibleConversionPrice1" />
    <loc xlink:href="arwr-20140331.xsd#arwr_NonCashConsiderationReceivedInSaleOfInterestInSubsidiaryBonds" xlink:type="locator" xlink:label="arwr_NonCashConsiderationReceivedInSaleOfInterestInSubsidiaryBonds" />
    <loc xlink:href="arwr-20140331.xsd#arwr_UnidymIncMember" xlink:type="locator" xlink:label="arwr_UnidymIncMember" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_RelatedPartyDomain" xlink:type="locator" xlink:label="us-gaap_RelatedPartyDomain" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_RelatedPartyTransactionsByRelatedPartyAxis" xlink:type="locator" xlink:label="us-gaap_RelatedPartyTransactionsByRelatedPartyAxis" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_InvestmentsFairValueDisclosure" xlink:type="locator" xlink:label="us-gaap_InvestmentsFairValueDisclosure" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_MarketableSecurities" xlink:type="locator" xlink:label="us-gaap_MarketableSecurities" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_MarketableSecuritiesNoncurrent" xlink:type="locator" xlink:label="us-gaap_MarketableSecuritiesNoncurrent" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_MarketableSecuritiesCurrent" xlink:type="locator" xlink:label="us-gaap_MarketableSecuritiesCurrent" />
    <loc xlink:href="arwr-20140331.xsd#arwr_FairValueMeasurementsDisclosureLineItems" xlink:type="locator" xlink:label="arwr_FairValueMeasurementsDisclosureLineItems" />
    <loc xlink:href="http://xbrl.sec.gov/dei/2013/dei-2013-01-31.xsd#dei_EntityDomain" xlink:type="locator" xlink:label="dei_EntityDomain" />
    <loc xlink:href="http://xbrl.sec.gov/dei/2013/dei-2013-01-31.xsd#dei_LegalEntityAxis" xlink:type="locator" xlink:label="dei_LegalEntityAxis" />
    <loc xlink:href="arwr-20140331.xsd#arwr_FairValueMeasurementsDisclosureTable" xlink:type="locator" xlink:label="arwr_FairValueMeasurementsDisclosureTable" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_FairValueDisclosuresAbstract" xlink:type="locator" xlink:label="us-gaap_FairValueDisclosuresAbstract" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueDisclosuresAbstract" xlink:to="arwr_FairValueMeasurementsDisclosureTable" order="10010.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="arwr_FairValueMeasurementsDisclosureTable" xlink:to="dei_LegalEntityAxis" order="10020.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="dei_LegalEntityAxis" xlink:to="dei_EntityDomain" order="10030.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="arwr_FairValueMeasurementsDisclosureTable" xlink:to="arwr_FairValueMeasurementsDisclosureLineItems" order="10040.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="arwr_FairValueMeasurementsDisclosureLineItems" xlink:to="us-gaap_MarketableSecuritiesCurrent" order="10080.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="arwr_FairValueMeasurementsDisclosureLineItems" xlink:to="us-gaap_MarketableSecuritiesNoncurrent" order="10100.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="arwr_FairValueMeasurementsDisclosureLineItems" xlink:to="us-gaap_MarketableSecurities" order="10120.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="arwr_FairValueMeasurementsDisclosureLineItems" xlink:to="us-gaap_InvestmentsFairValueDisclosure" order="10140.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="arwr_FairValueMeasurementsDisclosureTable" xlink:to="us-gaap_RelatedPartyTransactionsByRelatedPartyAxis" order="10020.02" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_RelatedPartyTransactionsByRelatedPartyAxis" xlink:to="us-gaap_RelatedPartyDomain" order="10190.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_RelatedPartyDomain" xlink:to="arwr_UnidymIncMember" order="10210.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="arwr_FairValueMeasurementsDisclosureLineItems" xlink:to="arwr_NonCashConsiderationReceivedInSaleOfInterestInSubsidiaryBonds" order="10290.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="arwr_FairValueMeasurementsDisclosureLineItems" xlink:to="us-gaap_DebtInstrumentConvertibleConversionPrice1" order="10350.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="arwr_FairValueMeasurementsDisclosureTable" xlink:to="us-gaap_ClassOfWarrantOrRightAxis" order="10020.04" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfWarrantOrRightAxis" xlink:to="us-gaap_ClassOfWarrantOrRightDomain" order="10440.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfWarrantOrRightDomain" xlink:to="arwr_TwoThousandTenWarrantsMember" order="10460.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfWarrantOrRightDomain" xlink:to="arwr_TwoThousandsTwelveWarrantsMember" order="10480.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ClassOfWarrantOrRightDomain" xlink:to="arwr_TwoThousandThirteenWarrantsMember" order="10500.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="arwr_FairValueMeasurementsDisclosureLineItems" xlink:to="arwr_WarrantsIssuedToAcquireCommonStock" order="10620.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="arwr_FairValueMeasurementsDisclosureLineItems" xlink:to="us-gaap_ClassOfWarrantOrRightOutstanding" order="10800.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="arwr_FairValueMeasurementsDisclosureLineItems" xlink:to="us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilityGainLossIncludedInEarnings" order="10980.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_RelatedPartyDomain" xlink:to="arwr_AblarisTherapeuticsMember" order="11090.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="arwr_FairValueMeasurementsDisclosureLineItems" xlink:to="arwr_TermOfExchangeRights" order="11210.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="arwr_FairValueMeasurementsDisclosureLineItems" xlink:to="arwr_ExchangeRightConvertibleConversionRatioForFirstYear" order="11270.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="arwr_FairValueMeasurementsDisclosureLineItems" xlink:to="arwr_ExchangeRightConvertibleConversionRatioForTwoYear" order="11330.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="arwr_FairValueMeasurementsDisclosureLineItems" xlink:to="arwr_ExchangeRightConvertibleConversionRatioForThreeYear" order="11390.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="arwr_FairValueMeasurementsDisclosureLineItems" xlink:to="arwr_ExchangeRightConvertibleConversionRatioForFourYear" order="11450.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="arwr_FairValueMeasurementsDisclosureLineItems" xlink:to="arwr_ExchangeRightConvertibleConversionRatioForFiveYear" order="11510.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="arwr_FairValueMeasurementsDisclosureLineItems" xlink:to="arwr_NumberOfExchangeRightAreSold" order="11570.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
  </presentationLink>
  <roleRef roleURI="http://www.arrowheadresearch.com/20140331/taxonomy/role/DisclosureFairValueMeasurementsAssumptionsUsedInValuingDerivativeAssetDetail" xlink:href="arwr-20140331.xsd#Role_DisclosureFairValueMeasurementsAssumptionsUsedInValuingDerivativeAssetDetail" xlink:type="simple" />
  <presentationLink xlink:type="extended" xlink:role="http://www.arrowheadresearch.com/20140331/taxonomy/role/DisclosureFairValueMeasurementsAssumptionsUsedInValuingDerivativeAssetDetail">
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_FairValueAssumptionsExpectedVolatilityRate" xlink:type="locator" xlink:label="us-gaap_FairValueAssumptionsExpectedVolatilityRate" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_FairValueAssumptionsExpectedDividendRate" xlink:type="locator" xlink:label="us-gaap_FairValueAssumptionsExpectedDividendRate" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_FairValueAssumptionsExpectedTerm" xlink:type="locator" xlink:label="us-gaap_FairValueAssumptionsExpectedTerm" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_FairValueAssumptionsRiskFreeInterestRate" xlink:type="locator" xlink:label="us-gaap_FairValueAssumptionsRiskFreeInterestRate" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems" xlink:type="locator" xlink:label="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DerivativeFinancialInstrumentsAssetsMember" xlink:type="locator" xlink:label="us-gaap_DerivativeFinancialInstrumentsAssetsMember" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain" xlink:type="locator" xlink:label="us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_FairValueByAssetClassAxis" xlink:type="locator" xlink:label="us-gaap_FairValueByAssetClassAxis" />
    <loc xlink:href="http://xbrl.sec.gov/dei/2013/dei-2013-01-31.xsd#dei_EntityDomain" xlink:type="locator" xlink:label="dei_EntityDomain" />
    <loc xlink:href="http://xbrl.sec.gov/dei/2013/dei-2013-01-31.xsd#dei_LegalEntityAxis" xlink:type="locator" xlink:label="dei_LegalEntityAxis" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable" xlink:type="locator" xlink:label="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_FairValueDisclosuresAbstract" xlink:type="locator" xlink:label="us-gaap_FairValueDisclosuresAbstract" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueDisclosuresAbstract" xlink:to="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable" order="10010.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable" xlink:to="dei_LegalEntityAxis" order="10020.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="dei_LegalEntityAxis" xlink:to="dei_EntityDomain" order="10030.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable" xlink:to="us-gaap_FairValueByAssetClassAxis" order="10020.02" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueByAssetClassAxis" xlink:to="us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain" order="10050.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain" xlink:to="us-gaap_DerivativeFinancialInstrumentsAssetsMember" order="10070.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable" xlink:to="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems" order="10150.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems" xlink:to="us-gaap_FairValueAssumptionsRiskFreeInterestRate" order="10190.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems" xlink:to="us-gaap_FairValueAssumptionsExpectedTerm" order="10270.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems" xlink:to="us-gaap_FairValueAssumptionsExpectedDividendRate" order="10350.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems" xlink:to="us-gaap_FairValueAssumptionsExpectedVolatilityRate" order="10430.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
  </presentationLink>
  <roleRef roleURI="http://www.arrowheadresearch.com/20140331/taxonomy/role/DisclosureFairValueMeasurementsReconciliationOfDerivativeAssetDetail" xlink:href="arwr-20140331.xsd#Role_DisclosureFairValueMeasurementsReconciliationOfDerivativeAssetDetail" xlink:type="simple" />
  <presentationLink xlink:type="extended" xlink:role="http://www.arrowheadresearch.com/20140331/taxonomy/role/DisclosureFairValueMeasurementsReconciliationOfDerivativeAssetDetail">
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetValue" xlink:type="locator" xlink:label="us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetValue_li0l2" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetSettlements" xlink:type="locator" xlink:label="us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetSettlements" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetGainLossIncludedInEarnings1" xlink:type="locator" xlink:label="us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetGainLossIncludedInEarnings1" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetPurchases" xlink:type="locator" xlink:label="us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetPurchases" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetValue" xlink:type="locator" xlink:label="us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetValue" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesLineItems" xlink:type="locator" xlink:label="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesLineItems" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_DerivativeFinancialInstrumentsAssetsMember" xlink:type="locator" xlink:label="us-gaap_DerivativeFinancialInstrumentsAssetsMember" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain" xlink:type="locator" xlink:label="us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_FairValueByAssetClassAxis" xlink:type="locator" xlink:label="us-gaap_FairValueByAssetClassAxis" />
    <loc xlink:href="http://xbrl.sec.gov/dei/2013/dei-2013-01-31.xsd#dei_EntityDomain" xlink:type="locator" xlink:label="dei_EntityDomain" />
    <loc xlink:href="http://xbrl.sec.gov/dei/2013/dei-2013-01-31.xsd#dei_LegalEntityAxis" xlink:type="locator" xlink:label="dei_LegalEntityAxis" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesTable" xlink:type="locator" xlink:label="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesTable" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_FairValueDisclosuresAbstract" xlink:type="locator" xlink:label="us-gaap_FairValueDisclosuresAbstract" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueDisclosuresAbstract" xlink:to="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesTable" order="10010.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesTable" xlink:to="dei_LegalEntityAxis" order="10020.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="dei_LegalEntityAxis" xlink:to="dei_EntityDomain" order="10030.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesTable" xlink:to="us-gaap_FairValueByAssetClassAxis" order="10020.02" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueByAssetClassAxis" xlink:to="us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain" order="10050.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain" xlink:to="us-gaap_DerivativeFinancialInstrumentsAssetsMember" order="10070.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesTable" xlink:to="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesLineItems" order="10090.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesLineItems" xlink:to="us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetValue" order="10130.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/periodStartLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesLineItems" xlink:to="us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetPurchases" order="10190.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesLineItems" xlink:to="us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetGainLossIncludedInEarnings1" order="10250.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesLineItems" xlink:to="us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetSettlements" order="10310.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesLineItems" xlink:to="us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisAssetValue_li0l2" order="10610.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/periodEndLabel" />
  </presentationLink>
  <roleRef roleURI="http://www.arrowheadresearch.com/20140331/taxonomy/role/DisclosureFairValueMeasurementsAssumptionsUsedInValuingDerivativeLiabilitiesDetail" xlink:href="arwr-20140331.xsd#Role_DisclosureFairValueMeasurementsAssumptionsUsedInValuingDerivativeLiabilitiesDetail" xlink:type="simple" />
  <presentationLink xlink:type="extended" xlink:role="http://www.arrowheadresearch.com/20140331/taxonomy/role/DisclosureFairValueMeasurementsAssumptionsUsedInValuingDerivativeLiabilitiesDetail">
    <loc xlink:href="arwr-20140331.xsd#arwr_ExchangeRightsMember" xlink:type="locator" xlink:label="arwr_ExchangeRightsMember" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_FairValueAssumptionsExpectedVolatilityRate" xlink:type="locator" xlink:label="us-gaap_FairValueAssumptionsExpectedVolatilityRate" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_FairValueAssumptionsExpectedDividendRate" xlink:type="locator" xlink:label="us-gaap_FairValueAssumptionsExpectedDividendRate" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_FairValueAssumptionsExpectedTerm" xlink:type="locator" xlink:label="us-gaap_FairValueAssumptionsExpectedTerm" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_FairValueAssumptionsRiskFreeInterestRate" xlink:type="locator" xlink:label="us-gaap_FairValueAssumptionsRiskFreeInterestRate" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesLineItems" xlink:type="locator" xlink:label="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesLineItems" />
    <loc xlink:href="arwr-20140331.xsd#arwr_TwoThousandThirteenWarrantsMember" xlink:type="locator" xlink:label="arwr_TwoThousandThirteenWarrantsMember" />
    <loc xlink:href="arwr-20140331.xsd#arwr_TwoThousandsTwelveWarrantsMember" xlink:type="locator" xlink:label="arwr_TwoThousandsTwelveWarrantsMember" />
    <loc xlink:href="arwr-20140331.xsd#arwr_TwoThousandTenWarrantsMember" xlink:type="locator" xlink:label="arwr_TwoThousandTenWarrantsMember" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationByLiabilityClassDomain" xlink:type="locator" xlink:label="us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationByLiabilityClassDomain" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_FairValueByLiabilityClassAxis" xlink:type="locator" xlink:label="us-gaap_FairValueByLiabilityClassAxis" />
    <loc xlink:href="http://xbrl.sec.gov/dei/2013/dei-2013-01-31.xsd#dei_EntityDomain" xlink:type="locator" xlink:label="dei_EntityDomain" />
    <loc xlink:href="http://xbrl.sec.gov/dei/2013/dei-2013-01-31.xsd#dei_LegalEntityAxis" xlink:type="locator" xlink:label="dei_LegalEntityAxis" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesTable" xlink:type="locator" xlink:label="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesTable" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_FairValueDisclosuresAbstract" xlink:type="locator" xlink:label="us-gaap_FairValueDisclosuresAbstract" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueDisclosuresAbstract" xlink:to="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesTable" order="10010.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesTable" xlink:to="dei_LegalEntityAxis" order="10020.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="dei_LegalEntityAxis" xlink:to="dei_EntityDomain" order="10030.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesTable" xlink:to="us-gaap_FairValueByLiabilityClassAxis" order="10020.02" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueByLiabilityClassAxis" xlink:to="us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationByLiabilityClassDomain" order="10050.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationByLiabilityClassDomain" xlink:to="arwr_TwoThousandTenWarrantsMember" order="10070.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationByLiabilityClassDomain" xlink:to="arwr_TwoThousandsTwelveWarrantsMember" order="10150.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationByLiabilityClassDomain" xlink:to="arwr_TwoThousandThirteenWarrantsMember" order="10230.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesTable" xlink:to="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesLineItems" order="10310.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesLineItems" xlink:to="us-gaap_FairValueAssumptionsRiskFreeInterestRate" order="10350.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesLineItems" xlink:to="us-gaap_FairValueAssumptionsExpectedTerm" order="10430.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesLineItems" xlink:to="us-gaap_FairValueAssumptionsExpectedDividendRate" order="10510.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesLineItems" xlink:to="us-gaap_FairValueAssumptionsExpectedVolatilityRate" order="10590.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationByLiabilityClassDomain" xlink:to="arwr_ExchangeRightsMember" order="11360.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
  </presentationLink>
  <roleRef roleURI="http://www.arrowheadresearch.com/20140331/taxonomy/role/DisclosureFairValueMeasurementsReconciliationOfDerivativeLiabilityDetail" xlink:href="arwr-20140331.xsd#Role_DisclosureFairValueMeasurementsReconciliationOfDerivativeLiabilityDetail" xlink:type="simple" />
  <presentationLink xlink:type="extended" xlink:role="http://www.arrowheadresearch.com/20140331/taxonomy/role/DisclosureFairValueMeasurementsReconciliationOfDerivativeLiabilityDetail">
    <loc xlink:href="arwr-20140331.xsd#arwr_ExchangeRightsMember" xlink:type="locator" xlink:label="arwr_ExchangeRightsMember" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationsRecurringBasisLiabilityValue" xlink:type="locator" xlink:label="us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationsRecurringBasisLiabilityValue_li0l2" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilitySettlements" xlink:type="locator" xlink:label="us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilitySettlements" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilityGainLossIncludedInEarnings" xlink:type="locator" xlink:label="us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilityGainLossIncludedInEarnings" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilityIssues" xlink:type="locator" xlink:label="us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilityIssues" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationsRecurringBasisLiabilityValue" xlink:type="locator" xlink:label="us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationsRecurringBasisLiabilityValue" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesLineItems" xlink:type="locator" xlink:label="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesLineItems" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_WarrantMember" xlink:type="locator" xlink:label="us-gaap_WarrantMember" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationByLiabilityClassDomain" xlink:type="locator" xlink:label="us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationByLiabilityClassDomain" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_FairValueByLiabilityClassAxis" xlink:type="locator" xlink:label="us-gaap_FairValueByLiabilityClassAxis" />
    <loc xlink:href="http://xbrl.sec.gov/dei/2013/dei-2013-01-31.xsd#dei_EntityDomain" xlink:type="locator" xlink:label="dei_EntityDomain" />
    <loc xlink:href="http://xbrl.sec.gov/dei/2013/dei-2013-01-31.xsd#dei_LegalEntityAxis" xlink:type="locator" xlink:label="dei_LegalEntityAxis" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesTable" xlink:type="locator" xlink:label="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesTable" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_FairValueDisclosuresAbstract" xlink:type="locator" xlink:label="us-gaap_FairValueDisclosuresAbstract" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueDisclosuresAbstract" xlink:to="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesTable" order="10010.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesTable" xlink:to="dei_LegalEntityAxis" order="10020.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="dei_LegalEntityAxis" xlink:to="dei_EntityDomain" order="10030.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesTable" xlink:to="us-gaap_FairValueByLiabilityClassAxis" order="10020.02" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueByLiabilityClassAxis" xlink:to="us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationByLiabilityClassDomain" order="10050.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationByLiabilityClassDomain" xlink:to="us-gaap_WarrantMember" order="10070.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesTable" xlink:to="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesLineItems" order="10250.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesLineItems" xlink:to="us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationsRecurringBasisLiabilityValue" order="10290.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/periodStartLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesLineItems" xlink:to="us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilityIssues" order="10350.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesLineItems" xlink:to="us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilityGainLossIncludedInEarnings" order="10410.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/verboseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesLineItems" xlink:to="us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilitySettlements" order="10470.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2009/role/negatedLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisValuationTechniquesLineItems" xlink:to="us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationsRecurringBasisLiabilityValue_li0l2" order="10770.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationByLiabilityClassDomain" xlink:to="arwr_ExchangeRightsMember" order="10880.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
  </presentationLink>
  <roleRef roleURI="http://www.arrowheadresearch.com/20140331/taxonomy/role/DisclosureFairValueMeasurementsChangeInFairValueOfContingentConsiderationObligationsDetail" xlink:href="arwr-20140331.xsd#Role_DisclosureFairValueMeasurementsChangeInFairValueOfContingentConsiderationObligationsDetail" xlink:type="simple" />
  <presentationLink xlink:type="extended" xlink:role="http://www.arrowheadresearch.com/20140331/taxonomy/role/DisclosureFairValueMeasurementsChangeInFairValueOfContingentConsiderationObligationsDetail">
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_BusinessCombinationContingentConsiderationLiability" xlink:type="locator" xlink:label="us-gaap_BusinessCombinationContingentConsiderationLiability_li0l2" />
    <loc xlink:href="arwr-20140331.xsd#arwr_BusinessCombinationFairValueOfChangeInContingentConsideration" xlink:type="locator" xlink:label="arwr_BusinessCombinationFairValueOfChangeInContingentConsideration" />
    <loc xlink:href="arwr-20140331.xsd#arwr_BusinessCombinationContingentConsiderationPayments" xlink:type="locator" xlink:label="arwr_BusinessCombinationContingentConsiderationPayments" />
    <loc xlink:href="arwr-20140331.xsd#arwr_BusinessCombinationPurchasePriceContingentConsiderationFairValue" xlink:type="locator" xlink:label="arwr_BusinessCombinationPurchasePriceContingentConsiderationFairValue" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_BusinessCombinationContingentConsiderationLiability" xlink:type="locator" xlink:label="us-gaap_BusinessCombinationContingentConsiderationLiability" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_BusinessAcquisitionContingentConsiderationLineItems" xlink:type="locator" xlink:label="us-gaap_BusinessAcquisitionContingentConsiderationLineItems" />
    <loc xlink:href="http://xbrl.sec.gov/dei/2013/dei-2013-01-31.xsd#dei_EntityDomain" xlink:type="locator" xlink:label="dei_EntityDomain" />
    <loc xlink:href="http://xbrl.sec.gov/dei/2013/dei-2013-01-31.xsd#dei_LegalEntityAxis" xlink:type="locator" xlink:label="dei_LegalEntityAxis" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionContingentConsiderationTable" xlink:type="locator" xlink:label="us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionContingentConsiderationTable" />
    <loc xlink:href="http://xbrl.fasb.org/us-gaap/2013/elts/us-gaap-2013-01-31.xsd#us-gaap_FairValueDisclosuresAbstract" xlink:type="locator" xlink:label="us-gaap_FairValueDisclosuresAbstract" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_FairValueDisclosuresAbstract" xlink:to="us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionContingentConsiderationTable" order="10010.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionContingentConsiderationTable" xlink:to="dei_LegalEntityAxis" order="10020.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="dei_LegalEntityAxis" xlink:to="dei_EntityDomain" order="10030.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionContingentConsiderationTable" xlink:to="us-gaap_BusinessAcquisitionContingentConsiderationLineItems" order="10040.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_BusinessAcquisitionContingentConsiderationLineItems" xlink:to="us-gaap_BusinessCombinationContingentConsiderationLiability" order="10080.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/periodStartLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_BusinessAcquisitionContingentConsiderationLineItems" xlink:to="arwr_BusinessCombinationPurchasePriceContingentConsiderationFairValue" order="10140.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_BusinessAcquisitionContingentConsiderationLineItems" xlink:to="arwr_BusinessCombinationContingentConsiderationPayments" order="10200.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_BusinessAcquisitionContingentConsiderationLineItems" xlink:to="arwr_BusinessCombinationFairValueOfChangeInContingentConsideration" order="10260.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/terseLabel" />
    <presentationArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/parent-child" xlink:from="us-gaap_BusinessAcquisitionContingentConsiderationLineItems" xlink:to="us-gaap_BusinessCombinationContingentConsiderationLiability_li0l2" order="10560.00" priority="2" use="optional" preferredLabel="http://www.xbrl.org/2003/role/periodEndLabel" />
  </presentationLink>
</linkbase>
