EXHIBIT 5




                                                     April 3, 2000



Xybernaut Corporation
12701 Fair Lakes Circle
Fairfax, Virginia  22033

Gentlemen:

         We  have  acted  as  counsel  to  Xybernaut  Corporation,   a  Delaware
corporation  (the "Company"),  in connection with the Registration  Statement on
Form S-3 (the  "Registration  Statement")  being filed with the  Securities  and
Exchange  Commission  under the Securities Act of 1933, as amended,  relating to
the offering of 2,843,301  shares (the "Shares") of Common Stock, par value $.01
per share (the "Common Stock").

          In  connection  with the  foregoing,  we have  examined  originals  or
copies,  satisfactory to us, of the Company's (i)  Certificate of  Incorporation
and (ii)  By-laws.  We have also reviewed such other matters of law and examined
and relied upon all such corporate records,  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 of all documents  submitted to us
as copies or facsimiles.  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  of  officers or other
representatives of the Company.

         Based upon and subject to the foregoing, we are of the opinion that the
Shares when sold will be validly issued, fully paid and non-assessable.

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

                                                           Very truly yours,

                                                           /s/ Parker Chapin LLP

                                                           PARKER CHAPIN LLP