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

    <schemaVersion>X0202</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2005-08-12</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000779390</issuerCik>
        <issuerName>ASPECT COMMUNICATIONS CORP</issuerName>
        <issuerTradingSymbol>ASPT</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001216494</rptOwnerCik>
            <rptOwnerName>VISTA EQUITY FUND II LP</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O VISTA EQUITY PARTNERS, LLC</rptOwnerStreet1>
            <rptOwnerStreet2>150 CALIFORNIA STREET, 19TH FLOOR</rptOwnerStreet2>
            <rptOwnerCity>SAN FRANCISCO</rptOwnerCity>
            <rptOwnerState>CA</rptOwnerState>
            <rptOwnerZipCode>94111</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001216495</rptOwnerCik>
            <rptOwnerName>VEFIIGP LLC</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1></rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity></rptOwnerCity>
            <rptOwnerState></rptOwnerState>
            <rptOwnerZipCode></rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001216497</rptOwnerCik>
            <rptOwnerName>SMITH ROBERT F</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1></rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity></rptOwnerCity>
            <rptOwnerState></rptOwnerState>
            <rptOwnerZipCode></rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock, par value $0.01 per share</value>
            </securityTitle>
            <transactionDate>
                <value>2005-08-12</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>C</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>17777777</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>2.25</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>17777777</value>
                    <footnoteId id="F1"/>
                    <footnoteId id="F2"/>
                    <footnoteId id="F3"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Series B Convertible Preferred Stock, par value $0.01 per sh</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>2.25</value>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2005-08-12</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>C</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>40000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <footnoteId id="F6"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <footnoteId id="F4"/>
            </exerciseDate>
            <expirationDate>
                <footnoteId id="F5"/>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock, par value $0.01 per share</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>17777777</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>10000</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">In addition to Vista Equity Fund II, L.P. (&quot;Vista&quot;), this form is filed by VEFIIGP, LLC (&quot;VEFIIGP&quot;) and Robert F. Smith (&quot;Mr. Smith&quot;).  VEFIIGP is the managing general partner of Vista; accordingly, securities owned by Vista may be regarded as being beneficially owned by VEFIIGP. Mr. Smith is the sole member of VEFIIGP; accordingly, securities beneficially owned by VEFIIGP may be regarded as being beneficially owned by Mr. Smith.  The addresses of both VEFIIGP and Mr. Smith are c/o Vista Equity Partners, LLC, 150 California Street, 19th Floor, San Francisco, California 94111.  Each of Vista, VEFIIGP and Mr. Smith disclaims beneficial ownership of securities owned by any other person or entity except to the extent of his or its respective pecuniary interest, if any, therein.</footnote>
        <footnote id="F2">Mr. Smith is a director of the Issuer.</footnote>
        <footnote id="F3">In connection with his position as a director of the Issuer, Mr. Smith has also acquired an aggregate of 9,795 shares of Common Stock in accordance with the terms of the Issuer's Annual Retainer Compensation Plan.</footnote>
        <footnote id="F4">The Series B Convertible Preferred Stock is convertible immediately upon its acquisition.</footnote>
        <footnote id="F5">Not applicable.</footnote>
        <footnote id="F6">Not applicable.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>VISTA EQUITY FUND II, L.P., By: VEFIIGP, LLC, its Managing General Partner, By: /s/ Robert F. Smith, Robert F. Smith, Managing Member</signatureName>
        <signatureDate>2005-08-16</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>VEFIIGP, LLC, By: /s/ Robert F. Smith, Robert F. Smith, Managing Member</signatureName>
        <signatureDate>2005-08-16</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>ROBERT F. SMITH, /s/ Robert F. Smith</signatureName>
        <signatureDate>2005-08-16</signatureDate>
    </ownerSignature>
</ownershipDocument>
