This study of 1,283 middle-school students examined the effect of an educational video designed to distinguish bullying from ordinary peer conflict. Randomly assigned classrooms of students either watched or did not watch a video prior to completing a self-report bullying survey. Compared to the control group, students who watched the video reported 32% less social bullying victimization, while boys who watched the video reported 54% less physical bullying victimization and 68% less physical bullying of others. These results indicate that student self-reports could yield inflated estimates of the prevalence of bullying if students are not adequately educated about the distinction between bullying and other forms of peer conflict. (Contains 4 tables.)