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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,
 JOQmVw6QlmikXCYVvWnDeFa+ac5AqVSVsTYFeYv5/9zmNXKlT5kO+B8XsHBTTQeE
 61FUt17nM7/TQphjHLaoUw==

<SEC-DOCUMENT>0001179110-09-015787.txt : 20091120
<SEC-HEADER>0001179110-09-015787.hdr.sgml : 20091120
<ACCEPTANCE-DATETIME>20091120153844
ACCESSION NUMBER:		0001179110-09-015787
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20091119
FILED AS OF DATE:		20091120
DATE AS OF CHANGE:		20091120

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			MONTGOMERY CHARLES D
		CENTRAL INDEX KEY:			0001347444

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-15725
		FILM NUMBER:		091198647

	MAIL ADDRESS:	
		STREET 1:		60 CENTURIAN DRIVE SUITE#112
		CITY:			MARKHAM
		STATE:			A6
		ZIP:			L3R 9R2

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			ALPHA PRO TECH LTD
		CENTRAL INDEX KEY:			0000884269
		STANDARD INDUSTRIAL CLASSIFICATION:	ORTHOPEDIC, PROSTHETIC & SURGICAL APPLIANCES & SUPPLIES [3842]
		IRS NUMBER:				631030494
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		60 CENTURIAN DR
		STREET 2:		SUITE 112
		CITY:			MARKHAM ONTARIO CANA
		STATE:			A6
		BUSINESS PHONE:		9054790654

	MAIL ADDRESS:	
		STREET 1:		60 CENTURION DR
		STREET 2:		STE 112
		CITY:			MARKHAM ON
		STATE:			A6

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	BFD INDUSTRIES INC
		DATE OF NAME CHANGE:	19930328
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>edgar.xml
<DESCRIPTION>FORM 4 -
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0303</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2009-11-19</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000884269</issuerCik>
        <issuerName>ALPHA PRO TECH LTD</issuerName>
        <issuerTradingSymbol>APT</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001347444</rptOwnerCik>
            <rptOwnerName>MONTGOMERY CHARLES D</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>60 CENTURIAN DRIVE SUITE 112</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>MARKHAM</rptOwnerCity>
            <rptOwnerState>A6</rptOwnerState>
            <rptOwnerZipCode>L3R 9R2</rptOwnerZipCode>
            <rptOwnerStateDescription>ONTARIO, CANADA</rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>Sr. V.P. Engineered Products</officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>common stock</value>
            </securityTitle>
            <transactionDate>
                <value>2009-11-19</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>S</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>50000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>5.11</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>121350</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeHolding>
            <securityTitle>
                <value>common stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>8270</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>by spouse, Mr. Montgomery disclaims beneficial ownership</value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <derivativeTable></derivativeTable>

    <footnotes></footnotes>

    <ownerSignature>
        <signatureName>Charles D. Montgomery</signatureName>
        <signatureDate>2009-11-20</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
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