<?xml version="1.0"?>

<ownershipDocument>

    <documentType>4</documentType>

    <periodOfReport>2003-05-13</periodOfReport>


    <notSubjectToSection16>1</notSubjectToSection16>

    <issuer>
        <issuerCik>0000840489</issuerCik>
        <issuerName>FIRST CASH FINANCIAL SERVICES INC</issuerName>
        <issuerTradingSymbol>FCFS</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001145839</rptOwnerCik>
            <rptOwnerName>DELTA PARTNERS LLC</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>  </rptOwnerStreet1>
            <rptOwnerStreet2>  </rptOwnerStreet2>
            <rptOwnerCity>  </rptOwnerCity>
            <rptOwnerState>  </rptOwnerState>
            <rptOwnerZipCode>  </rptOwnerZipCode>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>
    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001232598</rptOwnerCik>
            <rptOwnerName>ARGYROPLE CHRISTOPHER N</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>  </rptOwnerStreet1>
            <rptOwnerStreet2>  </rptOwnerStreet2>
            <rptOwnerCity>  </rptOwnerCity>
            <rptOwnerState>  </rptOwnerState>
            <rptOwnerZipCode>  </rptOwnerZipCode>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>
    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001232587</rptOwnerCik>
            <rptOwnerName>JOBSON CHARLES E</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>  </rptOwnerStreet1>
            <rptOwnerStreet2>  </rptOwnerStreet2>
            <rptOwnerCity>  </rptOwnerCity>
            <rptOwnerState>  </rptOwnerState>
            <rptOwnerZipCode>  </rptOwnerZipCode>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeSecurity>
        <securityTitle>
            <value>First Cash Financial Services Inc</value>
        </securityTitle>
        <transactionDate>
            <value>2003-05-13</value>
        </transactionDate>
        <transactionCoding>
            <transactionFormType>4</transactionFormType>
            <transactionCode>S</transactionCode>
            <equitySwapInvolved>0</equitySwapInvolved>
        </transactionCoding>
        <transactionTimeliness>
            <value></value>
        </transactionTimeliness>
        <transactionAmounts>
            <transactionShares>
                <value>4000</value>
            </transactionShares>
            <transactionValue>
                <value>11.83</value>
            </transactionValue>
            <transactionAcquiredDisposedCode>
                <value>D</value>
            </transactionAcquiredDisposedCode>
        </transactionAmounts>
        <postTransactionAmounts>
            <sharesOwnedFollowingTransaction>
                <value>886157</value>
            </sharesOwnedFollowingTransaction>
        </postTransactionAmounts>
        <ownershipNature>
            <directOrIndirectOwnership>
                <value>I</value>
            </directOrIndirectOwnership>
            <natureOfOwnership>
                <value>Indirect</value>
                <footnoteId id="F1"/>
            </natureOfOwnership>
        </ownershipNature>
    </nonDerivativeSecurity>

    <footnotes>
        <footnote id="F1">Reporting person Delta Partners, LLC is the Investment Manager of two private investment funds and is deemed to have investment discretion. The two funds are the actual owners of the issuer.

Reporting persons Charles E. Jobson and Christopher N. Argyrople are the Managing Members of the Investment Manager and can also be deemed to have investment discretion.

All reporting persons disclaim beneficial ownership in the shares reported herein except to the extent of their pecuniary interest.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>Christopher N Argyrople</signatureName>
        <signatureDate>2003-05-14</signatureDate>
    </ownerSignature>
    <ownerSignature>
        <signatureName>Charles E Jobson</signatureName>
        <signatureDate>2003-05-14</signatureDate>
    </ownerSignature>

</ownershipDocument>

