-----BEGIN PRIVACY-ENHANCED MESSAGE-----
Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
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MIC-Info: RSA-MD5,RSA,
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 zNlfMX6Y1HqnKMWbvzvEFg==

<SEC-DOCUMENT>0001140361-07-008552.txt : 20070427
<SEC-HEADER>0001140361-07-008552.hdr.sgml : 20070427
<ACCEPTANCE-DATETIME>20070427170617
ACCESSION NUMBER:		0001140361-07-008552
CONFORMED SUBMISSION TYPE:	4/A
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20070425
FILED AS OF DATE:		20070427
DATE AS OF CHANGE:		20070427

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

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			MOTTO WILLIAM J
		CENTRAL INDEX KEY:			0000940435

	FILING VALUES:
		FORM TYPE:		4/A
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	000-14902
		FILM NUMBER:		07796728

	BUSINESS ADDRESS:	
		STREET 1:		MERIDIAN DIAGNOSTICS INC
		STREET 2:		3471 RIVER HILLS DRIVE
		CITY:			CINCINNATI
		STATE:			OH
		ZIP:			45244
		BUSINESS PHONE:		5132713700

	MAIL ADDRESS:	
		STREET 1:		MERIDIAN BIOSCIENCE INC
		STREET 2:		3471 RIVER HILLS DRIVE
		CITY:			CINCINNATI
		STATE:			OH
		ZIP:			45244
</SEC-HEADER>
<DOCUMENT>
<TYPE>4/A
<SEQUENCE>1
<FILENAME>doc1.xml
<DESCRIPTION>FORM 4/A
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0202</schemaVersion>

    <documentType>4/A</documentType>

    <periodOfReport>2007-04-25</periodOfReport>

    <dateOfOriginalSubmission>2007-04-26</dateOfOriginalSubmission>

    <notSubjectToSection16>0</notSubjectToSection16>

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

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0000940435</rptOwnerCik>
            <rptOwnerName>MOTTO WILLIAM J</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>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>Chairman of the Board, CEO</officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>179325</value>
                    <footnoteId id="F1"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value></value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">This amendment corrects the previous Form 4 which reported the sale by Mr. Motto of 100,000 shares.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>Melissa Lueke as Attorney-in-Fact for William Motto</signatureName>
        <signatureDate>2007-04-27</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
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