<SEC-DOCUMENT>0001127602-24-013263.txt : 20240423
<SEC-HEADER>0001127602-24-013263.hdr.sgml : 20240423
<ACCEPTANCE-DATETIME>20240423163021
ACCESSION NUMBER:		0001127602-24-013263
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20240419
FILED AS OF DATE:		20240423
DATE AS OF CHANGE:		20240423

REPORTING-OWNER:	

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

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-36214
		FILM NUMBER:		24865195

	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]
		ORGANIZATION NAME:           	08 Industrial Applications and Services
		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>X0508</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2024-04-19</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>

    <aff10b5One>0</aff10b5One>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2024-04-19</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>G</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness></transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>12000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>1227088</value>
                    <footnoteId id="F1"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2024-04-22</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>G</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness></transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>12000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>1215088</value>
                    <footnoteId id="F1"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>1088954</value>
                    <footnoteId id="F2"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>MacMillan Family Trust</value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">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="F2">On April 19 and April 22, 2024, the Reporting Person contributed a total of 24,000 shares of common stock to the MacMillan Family Trust.  The Reporting Person is a trustee of the trust, and the Reporting Person and members of his family are the sole beneficiaries of the trust.  The Reporting Person is an indirect beneficial owner of the shares held by the trust.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>/s/ Mark W. Irving, attorney-in-fact for Mr. MacMillan</signatureName>
        <signatureDate>2024-04-23</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
