UNITED STATES
                       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                                            95-2579751
(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 Plans)

                               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 BOULEVARD, SUITE 525
                                ENCINO, CA 91436

                         CALCULATION OF REGISTRATION FEE
================================================================================
                                         Proposed       Proposed
                                         Maximum        Maximum
Title of Each Class                      Offering       Aggregate     Amount of
   of Securities        Amount To Be     Price Per      Offering    Registration
 To Be Registered      Registered (1)    Share (2)      Price (2)        Fee
- --------------------------------------------------------------------------------
Common Stock, par
  value $.0001 per
  share ...........       1,200,000        $15.715     $18,858,000    $2,219.59
================================================================================
(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.
(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 August 23, 2005.





         PURSUANT  TO  GENERAL  INSTRUCTION  E OF  FORM  S-8  ("REGISTRATION  OF
ADDITIONAL SECURITIES"), THE REGISTRANT 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),  on June 19,  2001,  the Company  filed with the
Securities  and  Exchange  Commission  a  Registration  Statement  on  Form  S-8
(Registration  No.  333-63304),  and on February 3, 2005, the Company filed with
the  Securities  and Exchange  Commission a  Registration  Statement on Form S-8
(Registration   No.   333-122501)   (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,  as
amended, 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 Chatsworth,  State of California,  on this 26th
day of August, 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, as amended,
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         President and Chief Executive        August 26, 2005
- ------------------------    Officer (Principal Executive
Cesar M. Garcia             Officer)


/s/ Martin G. Paravato      Chief Financial Officer and          August 26, 2005
- ------------------------    Secretary (Principal Financial
Martin G. Paravato          Officer and Principal Accounting
                            Officer)


/s/ Richard H. Williams     Chairman of the Board                August 26, 2005
- ------------------------
Richard H. Williams


/s/ Steven M. Besbeck       Director                             August 26, 2005
- ------------------------
Steven M. Besbeck


/s/ Thomas A. Adams         Director                             August 26, 2005
- ------------------------
Thomas A. Adams


/s/ Michael D. Matte        Director                             August 26, 2005
- ------------------------
Michael D. Matte


/s/ Richard G. Nadeau       Director                             August 26, 2005
- ------------------------
Richard G. Nadeau


                                       3



                                  EXHIBIT INDEX


EXHIBIT NO.       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 as part of the Signature  Page of
                  this Registration Statement).


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