The promoting responsibility through education and prevention (PREP) program is an after school substance abuse and violence prevention program for at-risk fourth and fifth grade youths in St. Louis, Missouri. Staffed by licensed clinical social workers and professional volunteers, PREP offers cultural cooking classes, yoga, and art as well as social skills building, substance use prevention, conflict resolution, and behavior management classes. Pre- and post-behavioral checklists were completed for four cohorts of PREP students, all of whom were African American (n = 88). For the latter two cohorts, there were significant improvements in social skills, a key protective factor in the prevention of substance abuse and violence. Youths in these cohorts received more programming and more therapeutic one-on-one support than students in the first two cohorts, suggesting that the expanded version of PREP may be an effective prevention program for African American at-risk children. (Contains 2 tables and 1 footnote.)