<SUBMISSION>
<ACCESSION-NUMBER>0000914190-03-000172
<TYPE>4
<PUBLIC-DOCUMENT-COUNT>1
<PERIOD>20031106
<FILING-DATE>20031202
<ISSUER>
<COMPANY-DATA>
<CONFORMED-NAME>SURMODICS INC
<CIK>0000924717
<ASSIGNED-SIC>2891
<IRS-NUMBER>411356149
<STATE-OF-INCORPORATION>MN
<FISCAL-YEAR-END>0930
</COMPANY-DATA>
<BUSINESS-ADDRESS>
<STREET1>9924 W 74TH ST
<CITY>EDEN PRAIRIE
<STATE>MN
<ZIP>55344
<PHONE>6128292700
</BUSINESS-ADDRESS>
<MAIL-ADDRESS>
<STREET1>9924 WEST 74TH ST
<CITY>EDEN PRAIRIE
<STATE>MN
<ZIP>55344
</MAIL-ADDRESS>
<FORMER-COMPANY>
<FORMER-CONFORMED-NAME>BSI CORP
<DATE-CHANGED>19970506
</FORMER-COMPANY>
</ISSUER>
<REPORTING-OWNER>
<OWNER-DATA>
<CONFORMED-NAME>KOCH DAVID A
<CIK>0001066677
</OWNER-DATA>
<FILING-VALUES>
<FORM-TYPE>4
<ACT>34
<FILE-NUMBER>000-23837
<FILM-NUMBER>031033460
</FILING-VALUES>
<BUSINESS-ADDRESS>
<STREET1>C/O TRUST U/W CLARISSA GRAY
<STREET2>505 N HIGHWAY 169 SUITE 595
<CITY>PLYMOUTH
<STATE>MN
<ZIP>55441
<PHONE>6123402600
</BUSINESS-ADDRESS>
<MAIL-ADDRESS>
<STREET1>C/O TRUST U/W CLARISSA GRAY
<STREET2>505 N HIGHWAY 169 SUITE 595
<CITY>PLYMOUTH
<STATE>MN
<ZIP>55441
</MAIL-ADDRESS>
</REPORTING-OWNER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>edgar.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>
    <schemaVersion>X0201</schemaVersion>

    <documentType>4</documentType><periodOfReport>2003-11-06</periodOfReport>
    <issuer>
        <issuerCik>0000924717</issuerCik>
        <issuerName>SURMODICS INC</issuerName>
        <issuerTradingSymbol>SRDX</issuerTradingSymbol></issuer><reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001066677</rptOwnerCik>
            <rptOwnerName>KOCH DAVID A</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>505 N. HIGHWAY 169</rptOwnerStreet1>
            <rptOwnerStreet2>SUITE 595</rptOwnerStreet2>
            <rptOwnerCity>PLYMOUTH</rptOwnerCity>
            <rptOwnerState>MN</rptOwnerState>
            <rptOwnerZipCode>55441</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
            <reportingOwnerRelationship>
<isDirector>1</isDirector><isOfficer>0</isOfficer><isTenPercentOwner>0</isTenPercentOwner><isOther>0</isOther></reportingOwnerRelationship></reportingOwner><nonDerivativeTable><nonDerivativeTransaction><securityTitle><value>Common Stock</value></securityTitle><transactionDate><value>2003-11-06</value></transactionDate><transactionCoding><transactionFormType>5</transactionFormType><transactionCode>G</transactionCode><equitySwapInvolved>0</equitySwapInvolved></transactionCoding><transactionAmounts><transactionShares><value>500</value></transactionShares><transactionPricePerShare><value>0</value></transactionPricePerShare><transactionAcquiredDisposedCode><value>A</value></transactionAcquiredDisposedCode></transactionAmounts><postTransactionAmounts><sharesOwnedFollowingTransaction><value>764220</value></sharesOwnedFollowingTransaction></postTransactionAmounts><ownershipNature><directOrIndirectOwnership><value>D</value></directOrIndirectOwnership><natureOfOwnership><value/></natureOfOwnership></ownershipNature></nonDerivativeTransaction><nonDerivativeTransaction><securityTitle><value>Common Stock</value></securityTitle><transactionDate><value>2003-11-26</value></transactionDate><transactionCoding><transactionFormType>4</transactionFormType><transactionCode>P</transactionCode><equitySwapInvolved>0</equitySwapInvolved></transactionCoding><transactionAmounts><transactionShares><value>10000</value></transactionShares><transactionPricePerShare><value>20.6436</value></transactionPricePerShare><transactionAcquiredDisposedCode><value>A</value></transactionAcquiredDisposedCode></transactionAmounts><postTransactionAmounts><sharesOwnedFollowingTransaction><value>774220</value></sharesOwnedFollowingTransaction></postTransactionAmounts><ownershipNature><directOrIndirectOwnership><value>D</value></directOrIndirectOwnership><natureOfOwnership><value/></natureOfOwnership></ownershipNature></nonDerivativeTransaction><nonDerivativeHolding><securityTitle><value>Common Stock</value></securityTitle><postTransactionAmounts><sharesOwnedFollowingTransaction><value>172000</value></sharesOwnedFollowingTransaction></postTransactionAmounts><ownershipNature><directOrIndirectOwnership><value>I</value></directOrIndirectOwnership><natureOfOwnership><value>Trust</value><footnoteId id="F1"/></natureOfOwnership></ownershipNature></nonDerivativeHolding></nonDerivativeTable><derivativeTable><derivativeHolding><securityTitle><value>Director Stock Option (Right to Buy)</value></securityTitle><conversionOrExercisePrice><value>6.563</value></conversionOrExercisePrice><exerciseDate><footnoteId id="F2"/></exerciseDate><expirationDate><value>2009-05-17</value></expirationDate><underlyingSecurity><underlyingSecurityTitle><value>Common Stock</value></underlyingSecurityTitle><underlyingSecurityShares><value>9000</value></underlyingSecurityShares></underlyingSecurity><postTransactionAmounts><sharesOwnedFollowingTransaction><value>9000</value></sharesOwnedFollowingTransaction></postTransactionAmounts><ownershipNature><directOrIndirectOwnership><value>D</value></directOrIndirectOwnership><natureOfOwnership><value/></natureOfOwnership></ownershipNature></derivativeHolding><derivativeHolding><securityTitle><value>Director Stock Option (Right to Buy)</value></securityTitle><conversionOrExercisePrice><value>2.50</value></conversionOrExercisePrice><exerciseDate><footnoteId id="F3"/></exerciseDate><expirationDate><value>2005-09-18</value></expirationDate><underlyingSecurity><underlyingSecurityTitle><value>Common Stock</value></underlyingSecurityTitle><underlyingSecurityShares><value>40000</value></underlyingSecurityShares></underlyingSecurity><postTransactionAmounts><sharesOwnedFollowingTransaction><value>40000</value></sharesOwnedFollowingTransaction></postTransactionAmounts><ownershipNature><directOrIndirectOwnership><value>D</value></directOrIndirectOwnership><natureOfOwnership><value/></natureOfOwnership></ownershipNature></derivativeHolding><derivativeHolding><securityTitle><value>Director Stock Option (Right to Buy)</value></securityTitle><conversionOrExercisePrice><value>25.094</value></conversionOrExercisePrice><exerciseDate><footnoteId id="F4"/></exerciseDate><expirationDate><value>2010-09-18</value></expirationDate><underlyingSecurity><underlyingSecurityTitle><value>Common Stock</value></underlyingSecurityTitle><underlyingSecurityShares><value>2000</value></underlyingSecurityShares></underlyingSecurity><postTransactionAmounts><sharesOwnedFollowingTransaction><value>2000</value></sharesOwnedFollowingTransaction></postTransactionAmounts><ownershipNature><directOrIndirectOwnership><value>D</value></directOrIndirectOwnership><natureOfOwnership><value/></natureOfOwnership></ownershipNature></derivativeHolding><derivativeHolding><securityTitle><value>Director Stock Option (Right to Buy)</value></securityTitle><conversionOrExercisePrice><value>34.85</value></conversionOrExercisePrice><exerciseDate><footnoteId id="F5"/></exerciseDate><expirationDate><value>2011-11-21</value></expirationDate><underlyingSecurity><underlyingSecurityTitle><value>Common Stock</value></underlyingSecurityTitle><underlyingSecurityShares><value>1000</value></underlyingSecurityShares></underlyingSecurity><postTransactionAmounts><sharesOwnedFollowingTransaction><value>1000</value></sharesOwnedFollowingTransaction></postTransactionAmounts><ownershipNature><directOrIndirectOwnership><value>D</value></directOrIndirectOwnership><natureOfOwnership><value/></natureOfOwnership></ownershipNature></derivativeHolding><derivativeHolding><securityTitle><value>Director Stock Option (Right to Buy)</value></securityTitle><conversionOrExercisePrice><value>29.17</value></conversionOrExercisePrice><exerciseDate><footnoteId id="F6"/></exerciseDate><expirationDate><value>2013-03-17</value></expirationDate><underlyingSecurity><underlyingSecurityTitle><value>Common Stock</value></underlyingSecurityTitle><underlyingSecurityShares><value>2000</value><footnoteId id="F7"/></underlyingSecurityShares></underlyingSecurity><postTransactionAmounts><sharesOwnedFollowingTransaction><value>2000</value><footnoteId id="F7"/></sharesOwnedFollowingTransaction></postTransactionAmounts><ownershipNature><directOrIndirectOwnership><value>D</value></directOrIndirectOwnership><natureOfOwnership><value/></natureOfOwnership></ownershipNature></derivativeHolding></derivativeTable><footnotes><footnote id="F1">These shares are owned by a trust established under the will of Clarissa L. Gray.  The wife and children of David A. Koch are among the beneficiaries of the trust.  The trustees of the trust are David A. Koch, Paul M. Torgerson and U.S. Bank Trust National Association SD.</footnote><footnote id="F2">Exercisable in annual increments of 1,800 shares each commencing 5/17/99.</footnote><footnote id="F3">Exercisable in annual increments of 8,000 shares each coommencing 9/18/95.</footnote><footnote id="F4">Exercisable in annual increments of 400 shares each commencing 9/18/00.</footnote><footnote id="F5">Exercisable in annual increments of 200 shares each commencing 11/21/01.</footnote><footnote id="F6">Exercisable in annual increments of 400 shares each commencing 3/17/03.</footnote><footnote id="F7">Revised to reflect correct number of shares which were inadvertently reported as 3,000.</footnote></footnotes><remarks/><ownerSignature><signatureName>David A. Koch</signatureName><signatureDate>2003-12-02</signatureDate></ownerSignature></ownershipDocument>

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</SUBMISSION>
