Recent studies indicate that bullying and being victimized by bullies is common among children in elementary and high schools, and can have a multitude of adverse effects ranging from poor school performance to suicide and homicide. This systematic review examined 26 studies evaluating the effectiveness of school-based interventions to prevent bullying; all 26 studies included elementary school students, and 6 included older students, as well. Interventions that consisted of classroom-level curricula seldom improved bullying prevalence. Likewise, social skills training was not very effective. In contrast, whole-school interventions addressing bullying as a systemic problem were effective. This study emphasizes that schools and communities should choose intervention programs wisely to reduce the victimization of children from bullying.