UNITED STATED
                       SECURITIES AND EXCHANGE COMMISSION
                             WASHINGTON, D.C. 20549
                                  -------------

                                    FORM S-8
                             REGISTRATION STATEMENT
                                      UNDER
                           THE SECURITIES ACT OF 1933
                                  -------------

                            IRIS INTERNATIONAL, INC.
             (Exact Name of Registrant as Specified in Its Charter)

                  DELAWARE                              94-2579751
      (State or Other Jurisdiction of               (I.R.S. Employer
       Incorporation or Organization)               Identification No.)

                      9172 ETON AVENUE
                   CHATSWORTH, CALIFORNIA                91311
        (Address of Principal Executive Offices)      (Zip Code)

                       1998 STOCK OPTION PLAN, AS AMENDED
                            (Full Title of the Plan)

                               MARTIN G. PARAVATO
                             CHIEF FINANCIAL OFFICER
                            IRIS INTERNATIONAL, INC.
                                9172 ETON AVENUE
                          CHATSWORTH, CALIFORNIA 91311
                     (Name and Address of Agent for Service)

                                 (818) 709-1244
          (Telephone Number, Including Area Code, of Agent for Service)
                                  -------------

                                   Copies to:

                               JOHN MCILVERY, ESQ.
                         STUBBS ALDERTON & MARKILES, LLP
                         15821 VENTURA BLVD., SUITE 525
                                ENCINO, CA 91436
                                 (818) 444-4500
                                  -------------

                         CALCULATION OF REGISTRATION FEE
================================================================================
                                        Proposed        Proposed
                                         Maximum        Maximum
                                        Offering       Aggregate      Amount of
Title of Securities    Amount To Be      Price          Offering    Registration
  To Be Registered    Registered (1)   Per Share (2)     Price          Fee
- -------------------   --------------   -------------   ---------    ------------
Common Stock, par
value $.001 per
share..............     1,000,000         $10.07      $10,070,000     $1,186
================================================================================
(1)  Pursuant to Rule 416(a) under the Securities Act of 1933, this Registration
     Statement  also covers such  additional  shares of the Common  Stock as may
     become issuable pursuant to the anti-dilution  provisions of the 1998 Stock
     Option Plan,  as amended.  In  addition,  pursuant to Rule 416(c) under the
     Securities  Act  of  1933,  this  Registration  Statement  also  covers  an
     indeterminate  amount of  securities  to be offered or sold pursuant to the
     1998 Stock Option Plan, as amended.
(2)  Estimated  solely for purposes of calculating the registration fee pursuant
     to Rule 457(h)(1)  under the Securities Act of 1933, as amended,  and based
     upon the  average of the high and low prices of the Common  Stock as quoted
     on the NASDAQ Stock Market on January 28, 2005.





         PURSUANT  TO  GENERAL  INSTRUCTION  E OF  FORM  S-8  ("REGISTRATION  OF
ADDITIONAL SECURITIES"), THE COMPANY HEREBY MAKES THE FOLLOWING STATEMENT:

         On October 9, 1998, IRIS International, Inc. (the "Company") filed with
the  Securities  and Exchange  Commission a  Registration  Statement on Form S-8
(Registration No.  333-65547),  on September 7, 2000, the Company filed with the
Securities  and  Exchange  Commission  a  Registration  Statement  on  Form  S-8
(Registration No.  333-45348),  and on June 19, 2001, the Company filed with the
Securities  and  Exchange  Commission  a  Registration  Statement  on  Form  S-8
(Registration No. 333-63304) (collectively, the "Prior Registration Statements")
relating to shares of the Common  Stock to be issued  pursuant to the  Company's
1998 Stock Option  Plan,  as amended (the  "Plan"),  and the Prior  Registration
Statements  are currently  effective.  This  Registration  Statement  relates to
securities  (a) of the same  class as those  to  which  the  Prior  Registration
Statements relate and (b) to be issued pursuant to the Plan. The contents of the
Prior Registration Statements are incorporated herein by reference.

         THE  FOLLOWING   EXHIBITS  ARE  FILED  AS  PART  OF  THIS  REGISTRATION
STATEMENT:

         5.1      Opinion of Stubbs Alderton & Markiles, LLP.

         23.1     Consent of BDO Seidman, LLP

         23.2     Consent  of Stubbs  Alderton  &  Markiles,  LLP  (included  in
                  Exhibit 5.1).

         24.1     Power of Attorney  (included as part of the Signature  Page of
                  this Registration Statement).


                                       2



                                   SIGNATURES

         Pursuant  to the  requirements  of the  Securities  Act  of  1933,  the
Registrant certifies that it has reasonable grounds to believe that it meets all
of the requirements for filing on Form S-8 and has duly caused this Registration
Statement  to be  signed  on its  behalf  by  the  undersigned,  thereunto  duly
authorized,  in the City of Los Angeles, State of California, on this 3rd day of
February, 2005.

                                 IRIS INTERNATIONAL, INC.
                                 (Registrant)

                                 By: /S/ CESAR M. GARCIA
                                     -------------------------------------------
                                     Cesar M. Garcia, Chief Executive Officer


                                 By: /S/ MARTIN G. PARAVATO
                                     -------------------------------------------
                                     Martin G. Paravato, Chief Financial Officer


                                POWER OF ATTORNEY

         Each person whose  signature  appears  below  constitutes  and appoints
Cesar M. Garcia and Martin G. Paravato, and each of them, as his true and lawful
attorneys-in-fact and agents with full power of substitution and resubstitution,
for him and his name, place and stead, in any and all capacities, to sign any or
all  amendments  (including  post-effective  amendments)  to  this  Registration
Statement and to file a new Registration Statement under Rule 461 or Instruction
E of Form S-8 of the Securities  Act of 1933, as amended,  and to file the same,
with all exhibits thereto, and other documents in connection therewith, with the
Securities and Exchange  Commission,  granting unto said  attorneys-in-fact  and
agents,  and each of them,  full power and  authority to do and perform each and
every  act and  thing  requisite  and  necessary  to be done  in and  about  the
foregoing,  as  fully to all  intents  and  purposes  as he might or could do in
person,  hereby  ratifying and  confirming all that said  attorneys-in-fact  and
agents, or either of them, or their substitutes,  may lawfully do or cause to be
done by virtue hereof.

         Pursuant  to the  requirements  of the  Securities  Act of  1933,  this
Registration  Statement  has been signed below by the  following  persons in the
capacities and on the date indicated.

          SIGNATURE                          TITLE                     DATE
          ---------                          -----                     ----

   /S/ CESAR M. GARCIA             Chief Executive Officer      February 3, 2005
- ----------------------------       and Director (Principal
       Cesar M. Garcia             Executive Officer)

   /S/ MARTIN G. PARAVATO          Chief Financial Officer      February 3, 2005
- ----------------------------       and Secretary (Principal
       Martin G. Paravato          Financial and Accounting
                                   Officer)

 /S/ RICHARD H. WILLIAMS           Director                     February 3, 2005
- ----------------------------
     Richard H. Williams

    /S/ STEVEN M. BESBECK          Director                     February 3, 2005
- ----------------------------
      Steven M. Besbeck

     /S/ THOMAS F. KELLEY          Director                     February 3, 2005
- ----------------------------
       Thomas F. Kelley

     /S/ RICHARD G. NADEAU         Director                     February 3, 2005
- ----------------------------
      Richard G. Nadeau

     /S/ MICHAEL D. MATTE          Director                     February 3, 2005
- ----------------------------
       Michael D. Matte


                                       3



                                  EXHIBIT INDEX

EXHIBIT
NUMBER                           EXHIBIT DESCRIPTION
- -------   ----------------------------------------------------------------------

  5.1     Opinion of Stubbs Alderton & Markiles, LLP.

 23.1     Consent of BDO Seidman, LLP.

 23.2     Consent of Stubbs Alderton & Markiles, LLP. (included in Exhibit 5.1).

 24.1     Power of Attorney (included on signature page).


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