Objective: To determine the effectiveness of group therapy in treating sexually abused children to prevent recidivism (subsequently re-abused or becoming abusers themselves). Methods: Recidivism rates of 617 children were compared between sexually abused children who received group treatment with those whose parents refused treatment. Additionally, pre- and post- YOQ 30.1 symptom ratings for 47 children were compared to also determine group therapy treatment effectiveness. Results: Sexually abused children who received group therapy treatment, in conjunction with group therapy provided to their parents are statistically the least likely to be revictimized or to become sexual abusers themselves, showing a moderate treatment size effect. Conclusions: Group therapy is an effective treatment for sexually abused children to prevent future recidivism.