<SUBMISSION>
<ACCESSION-NUMBER>0001181431-07-063694
<TYPE>4
<PUBLIC-DOCUMENT-COUNT>1
<PERIOD>20071022
<FILING-DATE>20071025
<DATE-OF-FILING-DATE-CHANGE>20071025
<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>
<REPORTING-OWNER>
<OWNER-DATA>
<CONFORMED-NAME>CASCELLA ROBERT
<CIK>0001218713
</OWNER-DATA>
<FILING-VALUES>
<FORM-TYPE>4
<ACT>34
<FILE-NUMBER>000-18281
<FILM-NUMBER>071189488
</FILING-VALUES>
<BUSINESS-ADDRESS>
<STREET1>C/O HOLOGIC INC
<STREET2>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>
</REPORTING-OWNER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>rrd175961.xml
<DESCRIPTION>FORM 4
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0202</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2007-10-22</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000859737</issuerCik>
        <issuerName>HOLOGIC INC</issuerName>
        <issuerTradingSymbol>HOLX</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001218713</rptOwnerCik>
            <rptOwnerName>CASCELLA ROBERT</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>35 CROSBY DRIVE</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>BEDFORD</rptOwnerCity>
            <rptOwnerState>MA</rptOwnerState>
            <rptOwnerZipCode>01730</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>President &amp; C.O.O.</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
                <footnoteId id="F1"/>
            </securityTitle>
            <transactionDate>
                <value>2007-10-22</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>15237</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0.00</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>18860</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
                <footnoteId id="F2"/>
            </securityTitle>
            <transactionDate>
                <value>2007-10-22</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>2666</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0.00</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>32307</value>
                    <footnoteId id="F3"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">These shares represent restricted stock units (RSUs) awarded to the Reporting Person pursuant to a retention agreement under the Hologic, Inc. Second Amended and Restated 1999 Stock Incentive Plan and are subject to vesting as provided in the retention agreement.</footnote>
        <footnote id="F2">These shares represent RSUs awarded to the Reporting Person pursuant to the Second Amended and Restated 1999 Stock Incentive Plan and are subject to vesting as provided in the agreement evidencing the award.</footnote>
        <footnote id="F3">Includes RSUs for 10,781 shares awarded to the Reporting Person on May 3, 2006 pursuant to a retention agreement under the Hologic, Inc. Second Amended and Restated 1999 Stock Incentive Plan and are subject to vesting as provided in the retention agreement. These shares were previously reported in Table II.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>/s/ Frances S. Crecco, Attorney-in-Fact For: Robert A. Cascella</signatureName>
        <signatureDate>2007-10-24</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SUBMISSION>
