<SEC-DOCUMENT>0000711377-13-000020.txt : 20130805
<SEC-HEADER>0000711377-13-000020.hdr.sgml : 20130805
<ACCEPTANCE-DATETIME>20130805190747
ACCESSION NUMBER:		0000711377-13-000020
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20130801
FILED AS OF DATE:		20130805
DATE AS OF CHANGE:		20130805

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

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			BOHANNON LON M
		CENTRAL INDEX KEY:			0001187556

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	000-17988
		FILM NUMBER:		131011474

	MAIL ADDRESS:	
		STREET 1:		NEOGEN CORP
		STREET 2:		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>2013-08-01</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

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

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001187556</rptOwnerCik>
            <rptOwnerName>BOHANNON LON M</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>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>President &amp; COO</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2013-08-01</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>S</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>23127</value>
                    <footnoteId id="F1"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>56.85</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>85878</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">The shares were sold under a 10b5-1(c) plan filed by the Registrant on 7/12/2013</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>Steven J. Quinlan (Attorney in Fact)</signatureName>
        <signatureDate>2013-08-05</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
