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

    <documentType>5</documentType><periodOfReport>2003-06-30</periodOfReport>
    <form3HoldingsReported>0</form3HoldingsReported>

    <form4TransactionsReported>0</form4TransactionsReported>

    <issuer>
        <issuerCik>0000057515</issuerCik>
        <issuerName>LANCASTER COLONY CORP</issuerName>
        <issuerTradingSymbol>LANC</issuerTradingSymbol></issuer><reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001220951</rptOwnerCik>
            <rptOwnerName>SEGAL DAVID M</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>LANCASTER COLONY CORPORATION</rptOwnerStreet1>
            <rptOwnerStreet2>37 W. BROAD STREET</rptOwnerStreet2>
            <rptOwnerCity>COLUMBUS</rptOwnerCity>
            <rptOwnerState>OH</rptOwnerState>
            <rptOwnerZipCode>43215</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
            <reportingOwnerRelationship>
<isDirector>0</isDirector><isOfficer>1</isOfficer><isTenPercentOwner>0</isTenPercentOwner><isOther>0</isOther><officerTitle>Secretary</officerTitle></reportingOwnerRelationship></reportingOwner><nonDerivativeTable><nonDerivativeTransaction><securityTitle><value>Common Stock Held in ESOP</value></securityTitle><transactionDate><value>2003-06-30</value></transactionDate><transactionCoding><transactionFormType>5</transactionFormType><transactionCode>J</transactionCode><equitySwapInvolved>0</equitySwapInvolved><footnoteId id="F1"/></transactionCoding><transactionAmounts><transactionShares><value>73.6806</value></transactionShares><transactionPricePerShare><value>0</value><footnoteId id="F2"/></transactionPricePerShare><transactionAcquiredDisposedCode><value>A</value></transactionAcquiredDisposedCode></transactionAmounts><postTransactionAmounts><sharesOwnedFollowingTransaction><value>3019.96</value><footnoteId id="F3"/></sharesOwnedFollowingTransaction></postTransactionAmounts><ownershipNature><directOrIndirectOwnership><value>D</value></directOrIndirectOwnership><natureOfOwnership><value/></natureOfOwnership></ownershipNature></nonDerivativeTransaction></nonDerivativeTable><footnotes><footnote id="F1">Fiscal year end distribution of shares into ESOP account</footnote><footnote id="F2">Shares purchaed in blocks, at various times and various prices, by ESOP Trustee and put in company sponsored ESOP to be allocated among all ESOP participants.</footnote><footnote id="F3">Common Stock: 2275 - D; Common Stock: 30 - I - by child</footnote></footnotes><remarks/><ownerSignature><signatureName>Patricia A. Schnieder POA for David M. Segal</signatureName><signatureDate>2003-08-01</signatureDate></ownerSignature></ownershipDocument>

