Objective: Six-month follow-up outcomes from a controlled trial of a program designed to prevent aggressive behavior in childhood are described. Method: Data were collected from three sequential cohorts of third graders in two public elementary schools (N =443). The Year 1 cohort received a routine health curriculum. The Year 2 cohort received the Making Choices program. The Year 3 cohort received the Making Choices program plus enhancements to promote behavioral generalization. Results: Six months after the end of prevention services, children in the intervention cohorts demonstrated significantly lower aggressive behavior when compared to children in the comparison cohort. The effects of the two programs were not significantly different. Conclusion: Both interventions appear to produce positive behavioral effects at follow-up.