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

    <schemaVersion>X0202</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2006-03-27</periodOfReport>

    <issuer>
        <issuerCik>0000889609</issuerCik>
        <issuerName>CONSUMER PORTFOLIO SERVICES INC</issuerName>
        <issuerTradingSymbol>CPSS</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001074001</rptOwnerCik>
            <rptOwnerName>LEVINE LEICHTMAN CAPITAL PARTNERS II LP</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>335 N. MAPLE DRIVE</rptOwnerStreet1>
            <rptOwnerStreet2>SUITE 240</rptOwnerStreet2>
            <rptOwnerCity>BEVERLY HILLS</rptOwnerCity>
            <rptOwnerState>CA</rptOwnerState>
            <rptOwnerZipCode>90210</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001259956</rptOwnerCik>
            <rptOwnerName>LLCP CALIFORNIA EQUITY PARTNERS II LP</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>335 N. MAPLE DRIVE</rptOwnerStreet1>
            <rptOwnerStreet2>SUITE 240</rptOwnerStreet2>
            <rptOwnerCity>BEVERLY HILLS</rptOwnerCity>
            <rptOwnerState>CA</rptOwnerState>
            <rptOwnerZipCode>90210</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001259957</rptOwnerCik>
            <rptOwnerName>LEVINE LEICHTMAN CAPITAL PARTNERS INC</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>335 N. MAPLE DRIVE</rptOwnerStreet1>
            <rptOwnerStreet2>SUITE 240</rptOwnerStreet2>
            <rptOwnerCity>BEVERLY HILLS</rptOwnerCity>
            <rptOwnerState>CA</rptOwnerState>
            <rptOwnerZipCode>90210</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001259958</rptOwnerCik>
            <rptOwnerName>LEVINE ARTHUR E</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>335 N. MAPLE DRIVE</rptOwnerStreet1>
            <rptOwnerStreet2>SUITE 240</rptOwnerStreet2>
            <rptOwnerCity>BEVERLY HILLS</rptOwnerCity>
            <rptOwnerState>CA</rptOwnerState>
            <rptOwnerZipCode>90210</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001259959</rptOwnerCik>
            <rptOwnerName>LEICHTMAN LAUREN B</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>335 N. MAPLE DRIVE</rptOwnerStreet1>
            <rptOwnerStreet2>SUITE 240</rptOwnerStreet2>
            <rptOwnerCity>BEVERLY HILLS</rptOwnerCity>
            <rptOwnerState>CA</rptOwnerState>
            <rptOwnerZipCode>90210</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock, no par value per share</value>
            </securityTitle>
            <transactionDate>
                <value>2006-03-27</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>S</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>20000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>8.3518</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>4532500</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                    <footnoteId id="F1"/>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value></value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock, no par value per share</value>
            </securityTitle>
            <transactionDate>
                <value>2006-03-28</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>S</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>8563</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>7.9119</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>4523937</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                    <footnoteId id="F1"/>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value></value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock, no par value per share</value>
            </securityTitle>
            <transactionDate>
                <value>2006-03-28</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>S</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>25032</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>8.0791</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>4498905</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                    <footnoteId id="F1"/>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value></value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">This Form 4 is being filed by more than one reporting person. Levine Leichtman Capital Partners II, L.P. (the &quot;Partnership&quot;) is the direct beneficial owner of the securities described above. LLCP California Equity Partners II, L.P. (the &quot;General Partner&quot;) is the sole general partner of the Partnership. Levine Leichtman Capital Partners, Inc. (&quot;Capital Corp.&quot;) is the sole general partner of the General Partner. Arthur E. Levine is a director and shareholder of, and the President of, Capital Corp. Lauren B. Leichtman is a director and shareholder of, and the Chief Executive Officer of, Capital Corp. Each of the General Partner, Capital Corp., Mr. Levine and Ms. Leichtman may be deemed to be an indirect beneficial owner of the equity securities reported herein and disclaims beneficial ownership of such equity securities except to the extent of his, her or its indirect pecuniary interest therein.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>/s/ Arthur E. Levine, President, on behalf of Levine Leichtman Capital Partners, Inc., the sole general partner of LLCP California Equity Partners II, L.P., the sole general partner of Levine Leichtman Capital Partners II, L.P.</signatureName>
        <signatureDate>2006-03-29</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>/s/ Arthur E. Levine, President, on behalf of Levine Leichtman Capital Partners, Inc., the sole general partner of LLCP California Equity Partners II, L.P.</signatureName>
        <signatureDate>2006-03-29</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>/s/ Arthur E. Levine, President, on behalf of Levine Leichtman Capital Partners, Inc.</signatureName>
        <signatureDate>2006-03-29</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>/s/ Arthur E. Levine</signatureName>
        <signatureDate>2006-03-29</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>/s/ Lauren B. Leichtman</signatureName>
        <signatureDate>2006-03-29</signatureDate>
    </ownerSignature>
</ownershipDocument>
