This mixed methods study describes attributions for improvement following reductions in victimization for children who were bullied at school. It also tests hypotheses from attribution theory about attributions associated with improvements. The sample was a subset of families who participated in an RCT of a family cognitive-behavioral program to reduce victimization; to be included, both the parent and child needed to report reductions in child victimization at 9 months. Attributions were compared across conditions, respondents (parents versus children) and time. Both parents and children attributed improvements most often to actions by the target child. Intervention families were more likely than control families to attribute changes to their own efforts than to external factors. The relevance of internal attributions for the success of interventions is discussed.