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

    <schemaVersion>X0202</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2004-09-01</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000874992</issuerCik>
        <issuerName>REMINGTON OIL &amp; GAS CORP</issuerName>
        <issuerTradingSymbol>REM</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0000947911</rptOwnerCik>
            <rptOwnerName>SIMPLOT J R</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>999 MAIN ST</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>BOISE</rptOwnerCity>
            <rptOwnerState>ID</rptOwnerState>
            <rptOwnerZipCode>83702</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</value>
            </securityTitle>
            <transactionDate>
                <value>2004-09-01</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>G</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>833333</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>4592595</value>
                    <footnoteId id="F1"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>See FN 2</value>
                    <footnoteId id="F2"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">See Table I, Item 7, Nature of Indirect Beneficial Interest.</footnote>
        <footnote id="F2">4,592,595 shares are directly owned by JRS Properties III LP (&quot;JRS Properties III&quot;).  (Of these shares, 950,000 shares are subject to previously-reported variable share forward sale contracts.)  The J.R. Simplot Self-Declaration of Revocable Trust (the &quot;Trust&quot;), of which Mr. J.R. Simplot is the beneficiary and trustee, controls JRS Properties III.  On September 1, 2004, JRS Properties III acquired 1,807,567 shares previously owned by JRS Properties LP (&quot;Properties&quot;) through the merger of Properties into JRS Properties III.  Properties was also controlled by the Trust and therefore the merger did not affect the aggregate beneficial ownership of the Trust and Mr. Simplot.  The Trust and a trust for the benefit of Mr. Simplot's spouse,which exercises no investment control, hold approximately 88% of the beneficial interest in the shares owned by JRS Properties III.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>J.R. Simplot, by Ronald N. Graves, as Attorney-in-Fact</signatureName>
        <signatureDate>2004-09-02</signatureDate>
    </ownerSignature>

    <ownerSignature>
        <signatureName>J.R. Simplot Self Declaration of Revocable Trust, by J.R. Simplot, Trustee, by Ronald N. Graves, as Attorney-in-Fact</signatureName>
        <signatureDate>2004-09-02</signatureDate>
    </ownerSignature>
</ownershipDocument>

