<SEC-DOCUMENT>0001127602-16-045089.txt : 20160304
<SEC-HEADER>0001127602-16-045089.hdr.sgml : 20160304
<ACCEPTANCE-DATETIME>20160304163712
ACCESSION NUMBER:		0001127602-16-045089
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20160302
FILED AS OF DATE:		20160304
DATE AS OF CHANGE:		20160304

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			HOLOGIC INC
		CENTRAL INDEX KEY:			0000859737
		STANDARD INDUSTRIAL CLASSIFICATION:	X-RAY APPARATUS & TUBES & RELATED IRRADIATION APPARATUS [3844]
		IRS NUMBER:				042902449
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			0924

	BUSINESS ADDRESS:	
		STREET 1:		250 CAMPUS DRIVE
		CITY:			MARLBOROUGH
		STATE:			MA
		ZIP:			01752
		BUSINESS PHONE:		5082632900

	MAIL ADDRESS:	
		STREET 1:		250 CAMPUS DRIVE
		CITY:			MARLBOROUGH
		STATE:			MA
		ZIP:			01752

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			MERKSAMER SAMUEL J.
		CENTRAL INDEX KEY:			0001501581

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-36214
		FILM NUMBER:		161485715

	MAIL ADDRESS:	
		STREET 1:		C/O ICAHN CAPITAL LP
		STREET 2:		767 FIFTH AVENUE, 47TH FLOOR
		CITY:			NEW YORK
		STATE:			NY
		ZIP:			10153

	FORMER NAME:	
		FORMER CONFORMED NAME:	MERKSAMER SAMUEL
		DATE OF NAME CHANGE:	20100920

	FORMER NAME:	
		FORMER CONFORMED NAME:	MERKSAMER SAM
		DATE OF NAME CHANGE:	20100917
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>form4.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2016-03-02</periodOfReport>

    <notSubjectToSection16>1</notSubjectToSection16>

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

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001501581</rptOwnerCik>
            <rptOwnerName>MERKSAMER SAMUEL J.</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O ICAHN CAPITAL LP</rptOwnerStreet1>
            <rptOwnerStreet2>767 FIFTH AVENUE, SUITE 4700</rptOwnerStreet2>
            <rptOwnerCity>NEW YORK</rptOwnerCity>
            <rptOwnerState>NY</rptOwnerState>
            <rptOwnerZipCode>10153</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <officerTitle></officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Non-qualified Stock Option (Right to Buy)</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>36.04</value>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2016-03-02</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness></transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>7402</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <footnoteId id="F1"/>
            </exerciseDate>
            <expirationDate>
                <value>2026-03-02</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>7402</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>7402</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeTransaction>
        <derivativeTransaction>
            <securityTitle>
                <value>Restricted Stock Unit Award (Right To Receive)</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <footnoteId id="F2"/>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2016-03-02</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness></transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>2427</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</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>2427</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>2427</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">Options become exercisable on the date of the 2017 Annual Meeting of Stockholders.  However, due to the Reporting Person's resignation from the Company's Board of Directors prior to the vesting date, these options have terminated.</footnote>
        <footnote id="F2">Restricted stock units (RSUs) convert into common stock on a one-for-one basis upon vesting.</footnote>
        <footnote id="F3">These RSUs vest and convert into shares of common stock on the date of the 2017 Annual Meeting of Stockholders.  However, due to the Reporting Person's resignation from the Company's Board of Directors prior to the vesting date, these RSUs have terminated.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>/s/ Patricia K. Dolan, attorney-in-fact for Mr. Merksamer</signatureName>
        <signatureDate>2016-03-04</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
