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                                                                     EXHIBIT 5.1



                                 July 15, 1997




International Remote Imaging Systems, Inc.
9162 Eton Avenue
Chatsworth, California  91311


         Re:  1997 Stock Option Plan
              ----------------------


Ladies and Gentlemen:

         We have acted as counsel to International Remote Imaging Systems, Inc.,
a Delaware corporation (the "Company"), in connection with its Registration
Statement on Form S-8 (the "Registration Statement") filed with the Securities
and Exchange Commission with respect to the registration of 600,000 shares of
common stock, $.01 par value, of the Company issuable under its 1997 Stock
Option Plan (the "Shares").

         As such counsel, we have examined such records, documents, certificates
and other instruments as in our judgment are necessary or appropriate in order
to enable us to render this opinion. Based on the foregoing and our examination
of such questions of law as we deem necessary, we are of the opinion that the
Shares will, when issued in accordance with the 1997 Stock Option Plan, be
validly issued, fully paid and non-assessable.

         We consent to the use of this opinion as an exhibit to the Registration
Statement. Except as set forth in this paragraph, this opinion is furnished
solely for your benefit and may not be relied upon by, nor copies delivered to,
any other person or entity without our prior written consent.



                                       Sincerely,


                                       /s/ Irell & Manella LLP

                                       Irell & Manella LLP