To test the efficacy of 2 programs designed to reduce high-risk behaviors among inner-city African American youth. Students in grades 5 through 8 and their parents and teachers from twelve metropolitan Chicago, Ill, schools and the communities they serve, were part of a cluster randomized trial from 1994 through 1998. The trials provided data on two separate approaches. The social development curriculum (SDC) consisted of 16 to 21 lessons per year focusing on social competence skills necessary to manage situations in which high-risk behaviors occur. The school/community intervention (SCI) consisted of SDC and school-wide climate and parent and community components. The control group received an attention-placebo health enhancement curriculum (HEC) of equal intensity to the SDC focusing on nutrition, physical activity, and general health care. Results indicate an impact differentiated by gender. Theoretically derived social-emotional programs that are culturally sensitive, developmentally appropriate, and offered in multiple grades can reduce multiple risk behaviors for inner-city African American boys in grades 5 through 8. The lack of effects for girls deserves further research.