-----BEGIN PRIVACY-ENHANCED MESSAGE-----
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,
 OVJWBQhsuPBzZiT+XVMqKNp0zPWHd+NclWDj9si9ssBs+yGfIHIyJtZUjq/w67+H
 WKtLUyPifVEg2/jwc5zhNg==

<SEC-DOCUMENT>0000726517-08-000017.txt : 20080512
<SEC-HEADER>0000726517-08-000017.hdr.sgml : 20080512
<ACCEPTANCE-DATETIME>20080512093853
ACCESSION NUMBER:		0000726517-08-000017
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20080509
FILED AS OF DATE:		20080512
DATE AS OF CHANGE:		20080512

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			MERCHANTS BANCSHARES INC
		CENTRAL INDEX KEY:			0000726517
		STANDARD INDUSTRIAL CLASSIFICATION:	STATE COMMERCIAL BANKS [6022]
		IRS NUMBER:				030287342
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		275 KENNEDY DRIVE
		CITY:			SOUTH BURLINGTON
		STATE:			VT
		ZIP:			05403
		BUSINESS PHONE:		8026583400

	MAIL ADDRESS:	
		STREET 1:		275 KENNEDY DRIVE
		CITY:			SOUTH BURLINGTON
		STATE:			VT
		ZIP:			05403

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			BOUYEA PETER A
		CENTRAL INDEX KEY:			0001220433

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	000-11595
		FILM NUMBER:		08820991

	BUSINESS ADDRESS:	
		BUSINESS PHONE:		8028651838

	MAIL ADDRESS:	
		STREET 1:		275 KENNEDY DRIVE
		CITY:			SOUTH BURLINGTON
		STATE:			VT
		ZIP:			05403
</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>2008-05-09</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000726517</issuerCik>
        <issuerName>MERCHANTS BANCSHARES INC</issuerName>
        <issuerTradingSymbol>mbvt</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001220433</rptOwnerCik>
            <rptOwnerName>BOUYEA PETER A</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>275 KENNEDY DRIVE</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>SOUTH BURLINGTON</rptOwnerCity>
            <rptOwnerState>VT</rptOwnerState>
            <rptOwnerZipCode>05403</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2008-05-09</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>P</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>239</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>23.5</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>78129</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <ownerSignature>
        <signatureName>Lisa A. Razo, P.O.A. for Peter A. Bouyea</signatureName>
        <signatureDate>2008-05-12</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
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