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

    <schemaVersion>X0202</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2005-02-01</periodOfReport>

    <issuer>
        <issuerCik>0001274913</issuerCik>
        <issuerName>INHIBITEX INC</issuerName>
        <issuerTradingSymbol>INHX</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001219855</rptOwnerCik>
            <rptOwnerName>BARRETT M JAMES</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>1119 ST. PAUL STREET</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>BALTIMORE</rptOwnerCity>
            <rptOwnerState>MD</rptOwnerState>
            <rptOwnerZipCode>21202</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Option (right to buy)</value>
                <footnoteId id="F1"/>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>8.995</value>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2005-02-01</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>6000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <value>2006-02-01</value>
            </exerciseDate>
            <expirationDate>
                <value>2011-02-01</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>6000</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>6000</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value></value>
                </natureOfOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">Granted pursuant to the 2004 Stock Incentive Plan.  The options shall fully vest upon the first anniversary of the date of grant.</footnote>
    </footnotes>

    <remarks>In addition to the shares reported herein, the Reporting Person is a general partner of NEA Partners 10, Limited Partnership, which is the sole general partner of New Enterprise Associates 10, Limited Partnership (&quot;NEA 10&quot;), the beneficial owner of (i) 5,140,482 common shares of the Issuer and warrants for 174,750 common shares of the Issuer, (ii) Series D warrants which if exercised would be convertible into 532,595 commons shares of the Issuer, and (iii) Series E warrants which if exercised would be convertible into 239,944 common shares of the Issuer.  The Reporting Person also is a manager of NEA 11 GP, LLC, which is the sole general partner of NEA Partners 11, Limited Partnership, which is in turn the sole general partner of New Enterprise  Associates 11, Limited Partnership (&quot;NEA 11&quot;), the beneficial owner of 1,355,470 common shares of the Issuer and warrants for 406,641 common shares of the Issuer.  These holdings have been previously reported.  The Reporting Person disclaims beneficial ownership, within the meaning of Section 16 of the Securities Act of 1934, as amended, of such portion of the NEA 10 shares and the NEA 11 shares in which the Reporting Person has no actual pecuniary interest therein.</remarks>

    <ownerSignature>
        <signatureName>Louis S. Citron, attorney-in-fact</signatureName>
        <signatureDate>2005-02-18</signatureDate>
    </ownerSignature>
</ownershipDocument>
