<?xml version="1.0"?>
<ownershipDocument>
    <schemaVersion>X0101</schemaVersion>

    <documentType>3</documentType><periodOfReport>2003-07-21</periodOfReport>
    <noSecuritiesOwned>1</noSecuritiesOwned>

    <issuer>
        <issuerCik>0001025996</issuerCik>
        <issuerName>KILROY REALTY CORP</issuerName>
        <issuerTradingSymbol>KRC</issuerTradingSymbol></issuer><reportingOwner><reportingOwnerId>
            <rptOwnerCik>0001256360</rptOwnerCik>
            <rptOwnerName>BRENNAN EDWARD F</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>  </rptOwnerStreet1>
            <rptOwnerStreet2>  </rptOwnerStreet2>
            <rptOwnerCity>  </rptOwnerCity>
            <rptOwnerState>  </rptOwnerState>
            <rptOwnerZipCode>  </rptOwnerZipCode>
        </reportingOwnerAddress>
            <reportingOwnerRelationship>
<isDirector>1</isDirector><isOfficer>0</isOfficer><isTenPercentOwner>0</isTenPercentOwner><isOther>0</isOther></reportingOwnerRelationship></reportingOwner><footnotes/><ownerSignature><signatureName>Tyler H. Rose, Treasurer, as attorney-in-fact for Edward F. Brennan</signatureName><signatureDate>2003-07-24</signatureDate></ownerSignature></ownershipDocument>

