<SUBMISSION>
<ACCESSION-NUMBER>0000007694-04-000196
<TYPE>4
<PUBLIC-DOCUMENT-COUNT>1
<PERIOD>20041215
<FILING-DATE>20041217
<DATE-OF-FILING-DATE-CHANGE>20041217
<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>CHAMBERS LAMAR M
<CIK>0001072302
</OWNER-DATA>
<FILING-VALUES>
<FORM-TYPE>4
<ACT>34
<FILE-NUMBER>001-02918
<FILM-NUMBER>041210910
</FILING-VALUES>
<BUSINESS-ADDRESS>
<STREET1>100 ASHLAND DRIVE
<STREET2>PO BOX 391
<CITY>RUSSELL
<STATE>KY
<ZIP>41169
<PHONE>6063293333
</BUSINESS-ADDRESS>
</REPORTING-OWNER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>c0001072302d20041217f4f.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0202</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2004-12-15</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

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

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001072302</rptOwnerCik>
            <rptOwnerName>CHAMBERS LAMAR M</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>50 E. RIVERCENTER BOULEVARD</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>COVINGTON</rptOwnerCity>
            <rptOwnerState>KY</rptOwnerState>
            <rptOwnerZipCode>41012-0391</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>Controller</officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>2917</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value></value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>3288</value>
                    <footnoteId id="F1"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>LESOP</value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>3292</value>
                    <footnoteId id="F2"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>401(K)</value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Common Stock Units</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>0</value>
                <footnoteId id="F3"/>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2004-12-15</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>J</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
                <footnoteId id="F4"/>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>79</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>58.23</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <footnoteId id="F4"/>
            </exerciseDate>
            <expirationDate>
                <footnoteId id="F4"/>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>79</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>18766</value>
                    <footnoteId id="F5"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value></value>
                </natureOfOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">Shares accrued under Ashland's Leveraged Employee Stock Ownership Plan as of 11-30-04.</footnote>
        <footnote id="F2">Based on Employee Savings Plan information as of 12-14-04, the latest date for which such information is reasonably available.</footnote>
        <footnote id="F3">1-for-1</footnote>
        <footnote id="F4">Common Stock Units acquired pursuant to Ashland's 1995 Deferred Compensation Plan as of 12-15-04, and exempt under Rule 16b-3(d).  (One (1) Common Stock Unit in the 1995 Deferred Compensation Plan is the equivalent of one (1) share of Ashland Common Stock)</footnote>
        <footnote id="F5">Common Stock Units acquired pursuant to Ashland's 1995 Deferred Compensation Plan as of 12-15-04, and exempt under Rule 16b-3(d).  (One (1) Common Stock Unit in the 1995 Deferred Compensation Plan is the equivalent of one (1) share of Ashland Common Stock)  This balance includes 18 shares that were omitted from the insider's previous filing due to an administrative error by the plan administrator.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>M. Craig Hall</signatureName>
        <signatureDate>2004-12-17</signatureDate>
    </ownerSignature>
</ownershipDocument>

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