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Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
Originator-Key-Asymmetric:
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 TWSM7vrzLADbmYQaionwg5sDW3P6oaM5D3tdezXMm7z1T+B+twIDAQAB
MIC-Info: RSA-MD5,RSA,
 T/T7zjcUsLpxLaAChLWc/uqZZQlUvbent2TxUx6BrxdBjPGwBrc7SU8bJhfpxUyQ
 3TEQgoBsXBIresKDzQhApA==

<SEC-DOCUMENT>0001127602-09-017906.txt : 20090825
<SEC-HEADER>0001127602-09-017906.hdr.sgml : 20090825
<ACCEPTANCE-DATETIME>20090825095628
ACCESSION NUMBER:		0001127602-09-017906
CONFORMED SUBMISSION TYPE:	4/A
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20090716
FILED AS OF DATE:		20090825
DATE AS OF CHANGE:		20090825

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Anderson James M.
		CENTRAL INDEX KEY:			0001468718

	FILING VALUES:
		FORM TYPE:		4/A
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	000-14902
		FILM NUMBER:		091032869

	MAIL ADDRESS:	
		STREET 1:		3471 RIVER HILLS DRIVE
		CITY:			CINCINNATI
		STATE:			OH
		ZIP:			45244

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			MERIDIAN BIOSCIENCE INC
		CENTRAL INDEX KEY:			0000794172
		STANDARD INDUSTRIAL CLASSIFICATION:	IN VITRO & IN VIVO DIAGNOSTIC SUBSTANCES [2835]
		IRS NUMBER:				310888197
		STATE OF INCORPORATION:			OH
		FISCAL YEAR END:			0930

	BUSINESS ADDRESS:	
		STREET 1:		3471 RIVER HILLS DR
		CITY:			CINCINNATI
		STATE:			OH
		ZIP:			45244
		BUSINESS PHONE:		5132713700

	MAIL ADDRESS:	
		STREET 1:		3471 RIVER HILLS DRIVE
		CITY:			CINCINNATI
		STATE:			OH
		ZIP:			45244

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	MERIDIAN DIAGNOSTICS INC
		DATE OF NAME CHANGE:	19920703
</SEC-HEADER>
<DOCUMENT>
<TYPE>4/A
<SEQUENCE>1
<FILENAME>form4a.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0303</schemaVersion>

    <documentType>4/A</documentType>

    <periodOfReport>2009-07-16</periodOfReport>

    <dateOfOriginalSubmission>2009-07-20</dateOfOriginalSubmission>

    <issuer>
        <issuerCik>0000794172</issuerCik>
        <issuerName>MERIDIAN BIOSCIENCE INC</issuerName>
        <issuerTradingSymbol>VIVO</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001468718</rptOwnerCik>
            <rptOwnerName>Anderson James M.</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>3471 RIVER HILLS DRIVE</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>CINCINNATI</rptOwnerCity>
            <rptOwnerState>OH</rptOwnerState>
            <rptOwnerZipCode>45244</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
        </reportingOwnerRelationship>
    </reportingOwner>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Stock Options (Right to Buy)</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>22.36</value>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2009-07-16</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness></transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>7500</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>22.36</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <footnoteId id="F1"/>
            </exerciseDate>
            <expirationDate>
                <value>2019-07-16</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>7500</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>7500</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">This award vests 25% every 90 days from the grant date.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>/s/ Melissa Lueke as Attorney-in-Fact for James M. Anderson</signatureName>
        <signatureDate>2009-08-25</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
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