X0305 4 2012-03-24 0000319240 IRIS INTERNATIONAL INC IRIS 0001343621 Yi John U C/O IRIS INTERNATIONAL, INC. 9158 ETON AVENUE CHATSWORTH CA 91311 0 1 0 0 Corp VP, Operations Common Stock 2012-03-24 4 M 0 1125 A 34333 I By Yi Family Trust UAD 1/10/01 Common Stock 2012-03-24 4 F 0 413 13.07 D 33920 I By Yi Family Trust UAD 1/10/01 Restricted Stock Units 2012-03-24 4 M 0 1125 0 D Common Stock 1125 3375 D Each restricted stock unit represents a contingent right to receive one share of IRIS International, Inc. common stock. On March 24, 2012, 1,125 of the reporting person's restricted stock units were settled for an equal number of shares of IRIS International, Inc. common stock. The shares were retained by the company in payment of the tax associated with the vesting of restricted shares and/or restricted stock units previously granted to the reporting person. Vested 25% on March 24, 2012 and thereafter 6.25% will vest in 12 equal quarterly installments with the first such installment vesting on June 30, 2012. Vested shares will be delivered to the reporting person as soon as practicable following the applicable vesting date. /s/ Todd M. Graham, Attorney-in-Fact 2012-03-27