-----BEGIN PRIVACY-ENHANCED MESSAGE-----
Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
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MIC-Info: RSA-MD5,RSA,
 Dsu5vZTKJMPicHFVLsLs9qPLDjlK7hn9E9Nl3WnOyrIsSMtOWZ2HSvF1XgcN6xI4
 5Yc94rvx6uLtZ+gQ+iSxFg==

<SEC-DOCUMENT>0001293462-08-000011.txt : 20080325
<SEC-HEADER>0001293462-08-000011.hdr.sgml : 20080325
<ACCEPTANCE-DATETIME>20080325172223
ACCESSION NUMBER:		0001293462-08-000011
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20080320
FILED AS OF DATE:		20080325
DATE AS OF CHANGE:		20080325

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Merselis James D
		CENTRAL INDEX KEY:			0001324910

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	000-30379
		FILM NUMBER:		08710119

	BUSINESS ADDRESS:	
		BUSINESS PHONE:		408-719-1393

	MAIL ADDRESS:	
		STREET 1:		C/O HEMOSENSE, INC.
		STREET 2:		651 RIVER OAKS PKWY
		CITY:			SAN JOSE
		STATE:			CA
		ZIP:			95134

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			CHEMBIO DIAGNOSTICS, INC.
		CENTRAL INDEX KEY:			0001092662
		STANDARD INDUSTRIAL CLASSIFICATION:	PHARMACEUTICAL PREPARATIONS [2834]
		IRS NUMBER:				880425691
		STATE OF INCORPORATION:			NV
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		3661 HORSEBLOCK ROAD
		CITY:			MEDFORD
		STATE:			NY
		ZIP:			11763
		BUSINESS PHONE:		(631) 924-1135

	MAIL ADDRESS:	
		STREET 1:		3661 HORSEBLOCK ROAD
		CITY:			MEDFORD
		STATE:			NY
		ZIP:			11763

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	Chembio Diagnostics Inc.
		DATE OF NAME CHANGE:	20040607

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	TRADING SOLUTIONS COM INC
		DATE OF NAME CHANGE:	19990805
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>primary_doc.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0202</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2008-03-20</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001092662</issuerCik>
        <issuerName>CHEMBIO DIAGNOSTICS, INC.</issuerName>
        <issuerTradingSymbol>CEMI</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001324910</rptOwnerCik>
            <rptOwnerName>Merselis James D</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O HEMOSENSE, INC.</rptOwnerStreet1>
            <rptOwnerStreet2>651 RIVER OAKS PKWY</rptOwnerStreet2>
            <rptOwnerCity>SAN JOSE</rptOwnerCity>
            <rptOwnerState>CA</rptOwnerState>
            <rptOwnerZipCode>95134</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Option to Purchase Common Stock</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>0.15</value>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2008-03-20</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>9000</value>
                    <footnoteId id="F1"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0.15</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <value>2008-03-20</value>
            </exerciseDate>
            <expirationDate>
                <value>2013-03-20</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>9000</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>9000</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">Options awarded for no cash consideration for Reporting Person's service as a member of the Company's Board of Directors.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>James D. Merselis</signatureName>
        <signatureDate>2008-03-25</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
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