<SUBMISSION>
<ACCESSION-NUMBER>0001181431-04-000812
<TYPE>4
<PUBLIC-DOCUMENT-COUNT>1
<PERIOD>20040101
<FILING-DATE>20040105
<REPORTING-OWNER>
<OWNER-DATA>
<CONFORMED-NAME>MUIR GLENN P
<CIK>0001181190
</OWNER-DATA>
<FILING-VALUES>
<FORM-TYPE>4
<ACT>34
<FILE-NUMBER>000-18281
<FILM-NUMBER>04505657
</FILING-VALUES>
<BUSINESS-ADDRESS>
<STREET1>C/O HOLOGIC
<STREET2>35 CROSBY DRIVE
<CITY>BEDFORD
<STATE>MA
<ZIP>01730
<PHONE>7819997377
</BUSINESS-ADDRESS>
</REPORTING-OWNER>
<ISSUER>
<COMPANY-DATA>
<CONFORMED-NAME>HOLOGIC INC
<CIK>0000859737
<ASSIGNED-SIC>3844
<IRS-NUMBER>042902449
<STATE-OF-INCORPORATION>DE
<FISCAL-YEAR-END>0930
</COMPANY-DATA>
<BUSINESS-ADDRESS>
<STREET1>35 CROSBY DRIVE
<CITY>BEDFORD
<STATE>MA
<ZIP>01730
<PHONE>7819997300
</BUSINESS-ADDRESS>
<MAIL-ADDRESS>
<STREET1>35 CROSBY DRIVE
<CITY>BEDFORD
<STATE>MA
<ZIP>01730
</MAIL-ADDRESS>
</ISSUER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>rrd27827.xml
<DESCRIPTION>FORM 4
<TEXT>
<XML>
<?xml version="1.0"?><ownershipDocument>
    <schemaVersion>X0201</schemaVersion>

    <documentType>4</documentType><periodOfReport>2004-01-01</periodOfReport><notSubjectToSection16>0</notSubjectToSection16>
    <issuer>
        <issuerCik>0000859737</issuerCik>
        <issuerName>HOLOGIC INC</issuerName>
        <issuerTradingSymbol>HOLX</issuerTradingSymbol></issuer><reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001181190</rptOwnerCik>
            <rptOwnerName>MUIR GLENN P</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>35 CROSBY DRIVE</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>BEDFORD</rptOwnerCity>
            <rptOwnerState>MA</rptOwnerState>
            <rptOwnerZipCode>01730</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
            <reportingOwnerRelationship>
<isDirector>1</isDirector><isOfficer>1</isOfficer><isTenPercentOwner>0</isTenPercentOwner><isOther>0</isOther><officerTitle>Executive VP and CFO</officerTitle></reportingOwnerRelationship></reportingOwner><nonDerivativeTable><nonDerivativeTransaction><securityTitle><value>Common Stock</value></securityTitle><transactionDate><value>2004-01-01</value></transactionDate><transactionCoding><transactionFormType>4</transactionFormType><transactionCode>I</transactionCode><equitySwapInvolved>0</equitySwapInvolved></transactionCoding><transactionAmounts><transactionShares><value>584</value><footnoteId id="F1"/></transactionShares><transactionPricePerShare><value>11.1350</value></transactionPricePerShare><transactionAcquiredDisposedCode><value>A</value></transactionAcquiredDisposedCode></transactionAmounts><postTransactionAmounts><sharesOwnedFollowingTransaction><value>40808</value></sharesOwnedFollowingTransaction></postTransactionAmounts><ownershipNature><directOrIndirectOwnership><value>D</value></directOrIndirectOwnership></ownershipNature></nonDerivativeTransaction></nonDerivativeTable><footnotes><footnote id="F1">Shares acquired under the Hologic Section 423 Employee Share Purchase Plan.</footnote></footnotes><ownerSignature><signatureName>/s/ Glenn P. Muir</signatureName><signatureDate>2004-01-05</signatureDate></ownerSignature></ownershipDocument>



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