This research investigated the effectiveness of a forgiveness education program on reducing anger and ethnic prejudice and improving forgiveness in Iranian adolescents. There were 224 (Persian, Azeri, and Kurdish) male and female students in 8th grade who were selected from 3 provinces: Tehran, Eastern Azerbaijan, and Kurdestan. Schools were randomly assigned to 2 groups of experimental (N = 123) and control (N = 101) students. Measures included the Enright Forgiveness Inventory, Spielberger's State-Trait Anger Expression Inventory, and the Ethnic Prejudice Scale, administered at pretest, posttest, and follow-up. The experimental group had forgiveness education by classroom teachers. The results indicated that the experimental group was higher in forgiveness and lower in ethnic prejudice, state anger, trait anger, and anger expression compared with the control group. This difference was statistically significant in the follow-up phase. It seems that forgiveness education in schools can be an important means of reducing anger and ethnic prejudice.