<SEC-DOCUMENT>0001127602-22-026759.txt : 20221202
<SEC-HEADER>0001127602-22-026759.hdr.sgml : 20221202
<ACCEPTANCE-DATETIME>20221202161248
ACCESSION NUMBER:		0001127602-22-026759
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20221130
FILED AS OF DATE:		20221202
DATE AS OF CHANGE:		20221202

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			MACMILLAN STEPHEN P
		CENTRAL INDEX KEY:			0001239351

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-36214
		FILM NUMBER:		221442070

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

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:			0928

	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
</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>2022-11-30</periodOfReport>

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

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001239351</rptOwnerCik>
            <rptOwnerName>MACMILLAN STEPHEN P</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>250 CAMPUS DRIVE</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>MARLBOROUGH</rptOwnerCity>
            <rptOwnerState>MA</rptOwnerState>
            <rptOwnerZipCode>01752</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>1</isOfficer>
            <officerTitle>Chairman, President and CEO</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2022-11-30</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>S</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness></transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>20999</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>75.434</value>
                    <footnoteId id="F1"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>2326471</value>
                    <footnoteId id="F2"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2022-11-30</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>S</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness></transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>12501</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>76.02</value>
                    <footnoteId id="F3"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>2313970</value>
                    <footnoteId id="F2"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">The price reported is the weighted average price per share.  Shares were sold in multiple transactions at prices ranging from $75.00 to $75.77 per share.  The Reporting Person will provide, upon request by the Commission staff, the Issuer or a security holder of the Issuer, full information regarding the number of shares sold at each price.</footnote>
        <footnote id="F2">Includes 1,079,673 restricted stock units/performance stock units, the settlement of which has been deferred pursuant to the Issuer's Deferred Equity Plan.</footnote>
        <footnote id="F3">The price reported is the weighted average price per share.  Shares were sold in multiple transactions at prices ranging from $75.80 to $76.17 per share.  The Reporting Person will provide, upon request by the Commission staff, the Issuer or a security holder of the Issuer, full information regarding the number of shares sold at each price.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>/s/ Mark W. Irving, attorney-in-fact for Mr. MacMillan</signatureName>
        <signatureDate>2022-12-02</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
