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

    <schemaVersion>X0202</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2004-05-20</periodOfReport>

    <issuer>
        <issuerCik>0000314808</issuerCik>
        <issuerName>ENSCO INTERNATIONAL INC</issuerName>
        <issuerTradingSymbol>ESV</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001191241</rptOwnerCik>
            <rptOwnerName>MALONE HERMAN E JR</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>500 N. AKARD STREET</rptOwnerStreet1>
            <rptOwnerStreet2>SUITE 4300</rptOwnerStreet2>
            <rptOwnerCity>DALLAS</rptOwnerCity>
            <rptOwnerState>TX</rptOwnerState>
            <rptOwnerZipCode>75201</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>Vice President</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2004-05-20</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>F</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>365</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>25.28</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>54372</value>
                    <footnoteId id="F1"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value></value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">In addition to his direct holdings the reporting person holds Indirect Beneficial Ownership of 12,042.109 shares of ENSCO common stock under the ENSCO Plans.  These indirect holdings include 10.382 shares of ENSCO common stock acquired between March 1, 2004 and April 30, 2004 through normal payroll contributions by the ENSCO Plans.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>H. E. Malone, Jr., Vice President</signatureName>
        <signatureDate>2004-05-21</signatureDate>
    </ownerSignature>
</ownershipDocument>

