<?xml version="1.0"?>
<ownershipDocument>
    <schemaVersion>X0201</schemaVersion>

    <documentType>4</documentType><periodOfReport>2003-12-16</periodOfReport>
    <issuer>
        <issuerCik>0000835324</issuerCik>
        <issuerName>S Y BANCORP INC</issuerName>
        <issuerTradingSymbol>SYI</issuerTradingSymbol></issuer><reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001193421</rptOwnerCik>
            <rptOwnerName>TASMAN NORMAN</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>6527 LONGVIEW LANE</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>LOUISVILLE</rptOwnerCity>
            <rptOwnerState>KY</rptOwnerState>
            <rptOwnerZipCode>40222</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
            <reportingOwnerRelationship>
<isDirector>1</isDirector><isOfficer>0</isOfficer><isTenPercentOwner>0</isTenPercentOwner><isOther>0</isOther></reportingOwnerRelationship></reportingOwner><derivativeTable><derivativeTransaction><securityTitle><value>Option (Right to Buy)</value></securityTitle><conversionOrExercisePrice><value>21.18</value></conversionOrExercisePrice><transactionDate><value>2003-12-16</value></transactionDate><transactionCoding><transactionFormType>4</transactionFormType><transactionCode>M</transactionCode><equitySwapInvolved>0</equitySwapInvolved></transactionCoding><transactionAmounts><transactionShares><value>1000</value></transactionShares><transactionPricePerShare><footnoteId id="F1"/></transactionPricePerShare><transactionAcquiredDisposedCode><value>A</value></transactionAcquiredDisposedCode></transactionAmounts><exerciseDate><value>2004-12-16</value></exerciseDate><expirationDate><value>2013-12-16</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></derivativeTransaction></derivativeTable><footnotes><footnote id="F1">Options granted (1,000) at $21.18 per share.  These options vest 20% per year.</footnote></footnotes><remarks>4,462 shares held by wife Indirectly. 12,541.527 shares held in Trust in the directors deferred comp plan Indirectly.   51,733.336 shares held Directly.  Derivative Securities:  4,800 nonqualified stock options @ 4.1875 held Directly.</remarks><ownerSignature><signatureName>//Norman Tasman</signatureName><signatureDate>2003-12-16</signatureDate></ownerSignature></ownershipDocument>

