<SEC-DOCUMENT>0000711377-19-000033.txt : 20190822
<SEC-HEADER>0000711377-19-000033.hdr.sgml : 20190822
<ACCEPTANCE-DATETIME>20190822162017
ACCESSION NUMBER:		0000711377-19-000033
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20180820
FILED AS OF DATE:		20190822
DATE AS OF CHANGE:		20190822

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			HERBERT JAMES L
		CENTRAL INDEX KEY:			0001168789

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	000-17988
		FILM NUMBER:		191046310

	MAIL ADDRESS:	
		STREET 1:		NEOGEN CORP
		STREET 2:		620 LESHER PLACE
		CITY:			LANSING
		STATE:			MI
		ZIP:			48912

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			NEOGEN CORP
		CENTRAL INDEX KEY:			0000711377
		STANDARD INDUSTRIAL CLASSIFICATION:	IN VITRO & IN VIVO DIAGNOSTIC SUBSTANCES [2835]
		IRS NUMBER:				382367843
		STATE OF INCORPORATION:			MI
		FISCAL YEAR END:			0531

	BUSINESS ADDRESS:	
		STREET 1:		620 LESHER PLACE
		CITY:			LANSING
		STATE:			MI
		ZIP:			48912
		BUSINESS PHONE:		5173729200

	MAIL ADDRESS:	
		STREET 1:		620 LESHER PLACE
		CITY:			LANSING
		STATE:			MI
		ZIP:			48912
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>primary_doc.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2018-08-20</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000711377</issuerCik>
        <issuerName>NEOGEN CORP</issuerName>
        <issuerTradingSymbol>NEOG</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001168789</rptOwnerCik>
            <rptOwnerName>HERBERT JAMES L</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>NEOGEN CORP</rptOwnerStreet1>
            <rptOwnerStreet2>620 LESHER PLACE</rptOwnerStreet2>
            <rptOwnerCity>LANSING</rptOwnerCity>
            <rptOwnerState>MI</rptOwnerState>
            <rptOwnerZipCode>48912</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2019-08-20</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>S</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>15000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>71.6739</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>267302</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>See Footnote</value>
                    <footnoteId id="F1"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>226970</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">Shares sold were out of the trust of Mr. Herbert's spouse; 7,434 remain in the trust. An additional 220,200 shares are held by limited liability companies in which Mr. Herbert and his spouse have minority financial position, 39,568 are held jointly by Mr. Herbert and his spouse, and 100 shares are held in a charitable remainder trust in which Mr. Herbert and his spouse are beneficiaries and trustees.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>Steven J Quinlan (Attorney in Fact)</signatureName>
        <signatureDate>2019-08-22</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
