(PARKER CHAPIN FLATTAU & KLIMPL, LLP Letterhead)


                                  July 11, 1996


Cellular Technical Services Company, Inc.
2401 Fourth Avenue
Seattle, Washington  98121

Gentlemen:

           We have acted as counsel to Cellular Technical Services Company, Inc.
(the  "Company") in connection  with a  Registration  Statement on Form S-8 (the
"Registration   Statement")   being  filed  with  the  Securities  and  Exchange
Commission  under  the  Securities  Act of 1933,  as  amended,  relating  to the
offering of  1,100,000  shares of common  stock,  $.001 par value per share (the
"Shares"),  pursuant  to options  granted or which may be granted by the Company
under its 1996 Stock Option Plan (the "Plan").

           In  connection  with the  foregoing,  we have  examined  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 of all 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 officers or other
representatives of the Company.

           Based upon and subject to the foregoing,  we are of the opinion that,
when  issued  and paid for in  accordance  with  the Plan and the  stock  option
contracts  evidencing  options  granted  thereunder,  the Shares will be validly
issued, fully paid and non-assessable.

           We hereby  consent  to filing of this  opinion  as an  Exhibit to the
Registration Statement.


                                        Very truly yours,


                                        /s/  PARKER CHAPIN FLATTAU & KLIMPL, LLP

                                        PARKER CHAPIN FLATTAU & KLIMPL, LLP