<?xml version="1.0"?>

<ownershipDocument>

    <schemaVersion>X0201</schemaVersion>

    <documentType>5</documentType>

    <periodOfReport>2003-10-31</periodOfReport>


    <notSubjectToSection16>0</notSubjectToSection16>

    <form3HoldingsReported>0</form3HoldingsReported>

    <form4TransactionsReported>0</form4TransactionsReported>

    <issuer>
        <issuerCik>0000277924</issuerCik>
        <issuerName>CREDO PETROLEUM CORP</issuerName>
        <issuerTradingSymbol>cred</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001186344</rptOwnerCik>
            <rptOwnerName>HUFFMAN JAMES T</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O CREDO PETROLEUM CORP</rptOwnerStreet1>
            <rptOwnerStreet2>1801 BROADWAY #900</rptOwnerStreet2>
            <rptOwnerCity>DENVER</rptOwnerCity>
            <rptOwnerState>CO</rptOwnerState>
            <rptOwnerZipCode>80202</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>President</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <derivativeTable>

        <derivativeTransaction>
            <securityTitle>
                <value>Stock Option (right to buy)</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>13.34</value>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2003-06-13</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>5</transactionFormType>
                <transactionCode>J</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>48250</value>
                    <footnoteId id="F1"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>13.34</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <value>2003-06-13</value>
            </exerciseDate>
            <expirationDate>
                <value>2013-06-13</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock $.10 par value</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>48250</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>48250</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeTransaction>

    </derivativeTable>

    <footnotes>
        <footnote id="F1">The purpose of this Form 5 is to correct an inadvertent calculation error that caused the total shares covered by options issued pursuant to the company's 1997 Stock Option Plan to exceed the total shares available for issuance under the Plan.  This Form 5 corrects information on Form 4 filed 6/17/2003.</footnote>
    </footnotes>


    <ownerSignature>
        <signatureName>James T. Huffman</signatureName>
        <signatureDate>2003-12-12</signatureDate>
    </ownerSignature>

</ownershipDocument>

