EXHIBIT 5

[LETTERHEAD OF MANATT, PHELPS & PHILLIPS, LLP]

May 13, 1997

National Mercantile Bancorp
1840 Century Park East
Los Angeles, CA  90067

           RE:  NATIONAL MERCANTILE BANCORP

Ladies and Gentlemen:

     As counsel for National Mercantile Bancorp, a California corporation (the
"Company"), in connection with the Company's Registration Statement on Form S-2,
No. 333-21455 as amended ("Registration Statement"), registering a maximum of
800,000 shares of the Company's noncumulative convertible preferred stock,
$10.00 stated valued (the "Preferred Stock") to be issued upon the exercise of
nontransferable rights to purchase Preferred Stock ("Rights") and upon the sale
of such shares to certain standby purchasers, and as further described in the
Registration Statement (the "Offering"), we have been requested to render this
opinion.

     We have examined and reviewed only such questions of law as we have deemed
necessary or appropriate for the purpose of rendering the opinion set forth
herein.

     For the purpose of rendering the opinion set forth herein, we have been
furnished with and examined only the following documents:

     1.  The Articles of Incorporation of the Company, as amended and presently
in effect;

     2.  The form of the Amended and Restated Articles of Incorporation of the 
Company (the "Restatement");

     3.  The Bylaws of the Company, as amended and presently in effect;

     4.  The Registration Statement;

     5.  Records of the meetings of the Board of Directors of the Company
pertaining to the Offering; and

     6.  Such other agreements, instruments, documents and records as we have
deemed to be necessary in connection with furnishing the opinion expressed
below.

     With respect to all of the foregoing documents, we have assumed, without
investigation, the genuineness of all signatures, the authenticity of all
documents submitted to us as originals and the conformity to originals of all
documents submitted to us as certified or reproduced

 
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copies.  We also have obtained from the officers of the Company such advice as
to such factual matters as we consider necessary for the purpose of this
opinion, and insofar as this opinion is based on such matters of fact, we have
relied on such advice.

     For the purposes of this opinion, we have further assumed that the 
Restatement will be duly authorized by the Board of Directors of the Company and
the shareholders of the Company, and will be filed with the Secretary of State 
for the State of California.

     Based on the foregoing, we are of the opinion that:

     (a) The shares of Preferred Stock when issued and delivered in the manner
and on the terms described in the Registration Statement (after and while the
Registration Statement is declared effective), will be validly issued, fully
paid and nonassessable.

     (b) The shares of the Company's common stock, no par value, issuable upon
conversion of the shares of Preferred Stock in the manner and on the terms
described in the Registration Statement, in accordance with the Restatement as
described in the Registration Statement, when issued upon such conversion in
accordance with the Restatement, will be validly issued, fully paid and
nonassessable.
    
     Our opinion expressed herein is limited to those matters expressly set
forth herein, and no opinion may be implied or inferred beyond the matters
expressly stated herein. We hereby disclaim any obligation to notify any person
or entity after the date hereof if any change in fact or law should change our
opinion with respect to any matter set forth in this letter.      
    
     This opinion is limited to the current laws of the State of California and
the United States of America, to present judicial interpretations thereof and to
facts as they presently exist. In rendering this opinion, we have no obligation
to revise or supplement it should the current laws of the State of California or
the United States of America be changed by legislative action, judicial decision
or otherwise.      


 
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     We hereby consent to the filing of this opinion as an exhibit to the
Registration Statement and to the reference to us under the caption "Legal
Matters" in the prospectus which is part of the Registration Statement.

                                   Respectfully submitted,




                                   /s/ Manatt, Phelps & Phillips, LLP