-----BEGIN PRIVACY-ENHANCED MESSAGE-----
Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
Originator-Key-Asymmetric:
 MFgwCgYEVQgBAQICAf8DSgAwRwJAW2sNKK9AVtBzYZmr6aGjlWyK3XmZv3dTINen
 TWSM7vrzLADbmYQaionwg5sDW3P6oaM5D3tdezXMm7z1T+B+twIDAQAB
MIC-Info: RSA-MD5,RSA,
 HyIqDAGbr+PA/SD175Xm3TQDxf1t2XkfslfbFCjTnHfgJA47kvtAyPxwzQJNPeld
 5772cHbThQGlZkttul6kAg==

<SEC-DOCUMENT>0001293462-08-000008.txt : 20080317
<SEC-HEADER>0001293462-08-000008.hdr.sgml : 20080317
<ACCEPTANCE-DATETIME>20080317163938
ACCESSION NUMBER:		0001293462-08-000008
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20080314
FILED AS OF DATE:		20080317
DATE AS OF CHANGE:		20080317

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Siebert Lawrence A.
		CENTRAL INDEX KEY:			0001291343

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	000-30379
		FILM NUMBER:		08693395

	BUSINESS ADDRESS:	
		BUSINESS PHONE:		631-924-1135

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

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>2008-03-14</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

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

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001291343</rptOwnerCik>
            <rptOwnerName>Siebert Lawrence A.</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>3661 HORSEBLOCK ROAD</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>MEDFORD</rptOwnerCity>
            <rptOwnerState>NY</rptOwnerState>
            <rptOwnerZipCode>11763</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>CEO</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2008-03-14</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>P</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>151000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0.15</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>5014874</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <ownerSignature>
        <signatureName>Lawrence A. Siebert</signatureName>
        <signatureDate>2007-03-17</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
-----END PRIVACY-ENHANCED MESSAGE-----