Exhibit 5.1

                 OPINION OF PARKER CHAPIN FLATTAU & KLIMPL, LLP
                                  [LETTERHEAD]

   
February 25, 1998
    

SmartServ Online, Inc.
One Station Place
Stamford, Connecticut 06902

Ladies and Gentlemen:

   
We have acted as counsel to SmartServ Online, Inc. (the "Company") in connection
with  Amendment  No.  1 to the  Registration  Statement  on Form S-3  (file  no.
333-39377) filed by the Company with the Securities and Exchange Commission (the
"Registration  Statement")  relating to up to 8,165,000 shares (the "Shares") of
the Company's Common Stock,  par value $0.01 per share (the "Common Stock").  Of
such Shares,  2,995,476 may be issued upon the exercise of Prepaid  Common Stock
Purchase  Warrants  which were issued to the holders of the Shares (the "Prepaid
Warrants").
    

In connection  with the  foregoing,  we have examined,  among other things,  the
Registration   Statement,   the  Prepaid   Warrants  and  originals  or  copies,
satisfactory  to us, of all such corporate  records and of all such  agreements,
certificates  and other  documents as we have deemed relevant and necessary as a
basis  for the  opinion  hereinafter  expressed.  In such  examination,  we have
assumed the  genuineness of all  signatures,  the  authenticity of all documents
submitted  to us as originals  and the  conformity  with the original  documents
submitted to us as copies. As to any facts material to such opinion, we have, to
the extent that relevant facts were not independently  established by us, relied
on certificates of public officials and certificates,  oaths and declarations of
officers or other representatives of the Company.

Based upon the  foregoing,  we are of the opinion that the Shares  issuable upon
the exercise of the Prepaid  Warrants (when such Shares are issued in accordance
with the terms of the Prepaid  Warrants) will be legally issued,  fully paid and
non-assessable.

We hereby  consent to the use of our name under the caption  "Legal  Matters" in
the  Prospectus  constituting  a part of the  Registration  Statement and to the
filing of a copy of this opinion as an exhibit.

Very truly yours,

/s/ Parker Chapin Flattau & Klimpl, LLP


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