-----BEGIN PRIVACY-ENHANCED MESSAGE-----
Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
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 TWSM7vrzLADbmYQaionwg5sDW3P6oaM5D3tdezXMm7z1T+B+twIDAQAB
MIC-Info: RSA-MD5,RSA,
 DgJkovSwM3DjBGB9R13RchbCGFjipkKRrI+UuKOk9UJExe25hQliWbBusv2JZDD4
 A8a6KB56kVxwEmPEPnsuzA==

<SEC-DOCUMENT>0001262014-05-000114.txt : 20051221
<SEC-HEADER>0001262014-05-000114.hdr.sgml : 20051221
<ACCEPTANCE-DATETIME>20051221162551
ACCESSION NUMBER:		0001262014-05-000114
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20051219
FILED AS OF DATE:		20051221
DATE AS OF CHANGE:		20051221

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			POHLAD WILLIAM M
		CENTRAL INDEX KEY:			0001061271
		STATE OF INCORPORATION:			MN
		FISCAL YEAR END:			1231

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-13015
		FILM NUMBER:		051278860

	BUSINESS ADDRESS:	
		STREET 1:		60 SOUTH SIXTH ST
		STREET 2:		STE 3800
		CITY:			MINNEAPOLIS
		STATE:			MN
		ZIP:			55402

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			NATIONAL MERCANTILE BANCORP
		CENTRAL INDEX KEY:			0000714801
		STANDARD INDUSTRIAL CLASSIFICATION:	STATE COMMERCIAL BANKS [6022]
		IRS NUMBER:				953819685
		STATE OF INCORPORATION:			CA
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		1840 CENTURY PARK EAST
		CITY:			LOS ANGELES
		STATE:			CA
		ZIP:			90067
		BUSINESS PHONE:		3102772265

	MAIL ADDRESS:	
		STREET 1:		1840 CENTURY PARK EAST
		CITY:			LOS ANGELES
		STATE:			CA
		ZIP:			90067
</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>2005-12-19</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000714801</issuerCik>
        <issuerName>NATIONAL MERCANTILE BANCORP</issuerName>
        <issuerTradingSymbol>MBLA</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001061271</rptOwnerCik>
            <rptOwnerName>POHLAD WILLIAM M</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>60 SOUTH 6TH STREET</rptOwnerStreet1>
            <rptOwnerStreet2>SUITE 4050</rptOwnerStreet2>
            <rptOwnerCity>MINNEAPOLIS</rptOwnerCity>
            <rptOwnerState>MN</rptOwnerState>
            <rptOwnerZipCode>55402</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2005-12-19</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>P</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>7000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>18.8781</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>655855</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Put Option (Obligation to Buy)</value>
                <footnoteId id="F1"/>
                <footnoteId id="F2"/>
            </securityTitle>
            <conversionOrExercisePrice>
                <footnoteId id="F1"/>
                <footnoteId id="F2"/>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2005-12-19</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>S</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>70316</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <footnoteId id="F1"/>
                <footnoteId id="F2"/>
            </exerciseDate>
            <expirationDate>
                <footnoteId id="F1"/>
                <footnoteId id="F2"/>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>70316</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>70316</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">The reporting person is a party to a Securities Purchase and Option Agreement dated December 19, 2005 by and among Scott A. Montgomery, Elaine B. Montgomery, The Montgomery Living Trust Dated September 28, 2000, James O. Pohlad, Robert C. Pohlad and William M. Pohlad (the &quot;Agreement&quot;).  Pursuant to the Agreement, the reporting person has (a) an obligation to purchase shares of common stock issuable upon exercise after December 31, 2005 of options granted to Scott A. Montgomery within 60 days of such exercise; (b) a right of first refusal to purchase shares of common stock Scott A. Montgomery, Elaine B. Montgomery or the Montgomery Trust proposes to transfer, whether voluntarily or involuntarily, other than for certain excluded transfers; (c) the right to purchase shares of common stock issuable upon exercise prior to December 31, 2005 granted to Scott A. Montgomery on the first business day following the one year anniversary of exercise of options prior to December 31, 200
5; and</footnote>
        <footnote id="F2">(d) an obligation to purchase shares of common stock held by Scott A. Montgomery, Elaine B. Montgomery or The Montgomery Trust or shares of common stock underlying options held by Scott A. Montgomery upon termination of Scott A. Montgomery's employment.  For the purposes of the Agreement, the purchase price is determined with reference to the closing price as reported on the Nasdaq SmallCap Market or book value per share of the common stock.  The Agreement covers options to purchase 186,008 shares of common stock issuable upon exercise of outstanding options held by Scott A. Montgomery, 45,938 shares held by The Montgomery Trust and any other shares of common stock acquired by Scott A. Montgomery, Elaine B. Montgomery or The Montgomery Trust prior to the termination of Scott A. Montgomery's employment with the National Mercantile Bancorp and the purchase rights and obligations of the reporting person are with respect to one-third of such shares.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>/s/  William M. Pohlad</signatureName>
        <signatureDate>2005-12-19</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
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