<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0202</schemaVersion>

    <documentType>3</documentType>

    <periodOfReport>2004-10-01</periodOfReport>

    <noSecuritiesOwned>0</noSecuritiesOwned>

    <issuer>
        <issuerCik>0001168478</issuerCik>
        <issuerName>HEWITT ASSOCIATES INC</issuerName>
        <issuerTradingSymbol>HEW</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001193340</rptOwnerCik>
            <rptOwnerName>DENNING STEVEN A</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O GENERAL ATLANTIC SERVICE CORPORATION</rptOwnerStreet1>
            <rptOwnerStreet2>3 PICKWICK PLAZA</rptOwnerStreet2>
            <rptOwnerCity>GREENWICH</rptOwnerCity>
            <rptOwnerState>CT</rptOwnerState>
            <rptOwnerZipCode>06830</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>9774479</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>See</value>
                    <footnoteId id="F1"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>12000</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value></value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">Consists of 4,661,962 shares owned by General Atlantic Partners 54, L.P. (&quot;GAP 54&quot;), 1,115,353 shares owned by General Atlantic Partners 57, L.P. (&quot;GAP 57&quot;), 2,180,207 shares owned by General Atlantic Partners 60, L.P. (&quot;GAP 60&quot;), 775,805 shares owned by GAP Coinvestment Partners, L.P. (&quot;GAPCO&quot;) and 1,041,152 shares owned by GAP Coinvestment Partners II, L.P. (&quot;GAPCO II&quot;).  General Atlantic Partners, LLC (&quot;GAP LLC&quot;) is the general partner of each of GAP 54, GAP 57 and GAP 60.  The general partners of GAPCO and GAPCO II are managing members of GAP LLC.  The Reporting Person is a managing member of GAP LLC and a general partner of GAPCO and GAPCO II, and disclaims beneficial ownership of such shares except to the extent of his pecuniary interest therein.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>Steven A. Denning</signatureName>
        <signatureDate>2004-10-04</signatureDate>
    </ownerSignature>
</ownershipDocument>

