<SUBMISSION>
<ACCESSION-NUMBER>0000007694-04-000039
<TYPE>4
<PUBLIC-DOCUMENT-COUNT>1
<PERIOD>20040331
<FILING-DATE>20040402
<ISSUER>
<COMPANY-DATA>
<CONFORMED-NAME>ASHLAND INC
<CIK>0000007694
<ASSIGNED-SIC>5160
<IRS-NUMBER>610122250
<STATE-OF-INCORPORATION>KY
<FISCAL-YEAR-END>0930
</COMPANY-DATA>
<BUSINESS-ADDRESS>
<STREET1>50 E. RIVERCENTER BOULEVARD
<CITY>COVINGTON
<STATE>KY
<ZIP>41012
<PHONE>6068153333
</BUSINESS-ADDRESS>
<MAIL-ADDRESS>
<STREET1>50 E. RIVERCENTER BOULEVARD
<CITY>COVINGTON
<STATE>KY
<ZIP>41012
</MAIL-ADDRESS>
<FORMER-COMPANY>
<FORMER-CONFORMED-NAME>ASHLAND OIL INC
<DATE-CHANGED>19920703
</FORMER-COMPANY>
<FORMER-COMPANY>
<FORMER-CONFORMED-NAME>ASHLAND OIL & REFINING CO
<DATE-CHANGED>19700806
</FORMER-COMPANY>
</ISSUER>
<REPORTING-OWNER>
<OWNER-DATA>
<CONFORMED-NAME>JACKSON MANNIE L
<CIK>0001026050
<STATE-OF-INCORPORATION>KY
<FISCAL-YEAR-END>0930
</OWNER-DATA>
<FILING-VALUES>
<FORM-TYPE>4
<ACT>34
<FILE-NUMBER>001-02918
<FILM-NUMBER>04712200
</FILING-VALUES>
<BUSINESS-ADDRESS>
<STREET1>ONE ARIZONA CENTER
<STREET2>400 EAST VAN BUREN STREET SUITE 300
<CITY>NEW YORK
<STATE>NY
<ZIP>10111-0242
<PHONE>6063293333
</BUSINESS-ADDRESS>
<MAIL-ADDRESS>
<STREET1>ALFRED P SLOAN FOUNDATION
<STREET2>630 FIFTH AVENUE SUITE 2550
<CITY>NEW YORK
<STATE>NY
<ZIP>10111-0242
</MAIL-ADDRESS>
</REPORTING-OWNER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>c0001026050d20040402f4f.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0201</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2004-03-31</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000007694</issuerCik>
        <issuerName>ASHLAND INC</issuerName>
        <issuerTradingSymbol>ASH</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001026050</rptOwnerCik>
            <rptOwnerName>JACKSON MANNIE L</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>HARLEM GLOBETROTTERS INTERNATIONAL</rptOwnerStreet1>
            <rptOwnerStreet2>400 EAST VAN BUREN STREET, SUITE 300</rptOwnerStreet2>
            <rptOwnerCity>PHOENIX</rptOwnerCity>
            <rptOwnerState>AZ</rptOwnerState>
            <rptOwnerZipCode>85004</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle></officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>2000</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value></value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Restricted Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>1000</value>
                    <footnoteId id="F1"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value></value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Common Stock Units</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>0</value>
                <footnoteId id="F2"/>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2004-03-31</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>J</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
                <footnoteId id="F3"/>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>581</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>46.49</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <footnoteId id="F3"/>
            </exerciseDate>
            <expirationDate>
                <footnoteId id="F3"/>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>581</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>23720</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value></value>
                </natureOfOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">Represents shares of Restricted Common Stock acquired pursuant to Ashland's stock incentive plans as approved by the shareholders and exempt pursuant to Rule 16b-3.</footnote>
        <footnote id="F2">Converts to common stock on a one-for-one basis.</footnote>
        <footnote id="F3">Common Stock Units acquired pursuant to Ashland's Deferred Compensation Plan for Non-Employee Directors as of 3-31-04, payable in cash or stock upon termination of service and exempt under Rule 16b-3.  (One (1) Common Stock Unit in the Deferred Compensation Plan for Non-Employee Directors is the equivalent of one (1) share of Ashland Common Stock)</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>M. Craig Hall</signatureName>
        <signatureDate>2004-04-02</signatureDate>
    </ownerSignature>
</ownershipDocument>

</XML>
</TEXT>
</DOCUMENT>
</SUBMISSION>
