Objectives:This study aims to investigate the effectiveness of an internet-based anger management program for school-aged children. Methods:Forty-eight elementary school students took part in an anger management training program; subsequently, participants, their parents, and their teachers answered questionnaires assessing the participants’anger, aggressiveness, and other emotional/ behavioral problems, pre- and post-training. Results:At the post-training self-assessment, the participants showed significant reductions in their “anger-out” tendencies and physical aggressiveness. In addition, the effects of the program on “anger-out” tendencies, aggressiveness, anger and peer relational problem were found to be more significant in participants who reported depressive symptoms. Teachers rated the participants’ peer-relational problems as having decreased after the training. Conclusion:The proposed internet-based anger management program had a significant effect on the school-aged children’s abilities to control their anger.