The present study reports on the effectiveness at one-year follow-up of an after-school prevention program targeting 6th grade African American youth residing in high-risk urban areas. The program, conducted on-site over the school-year period, involved a group mentoring approach emphasizing remedial education and an appreciation of African American cultural heritage in promoting school bonding, social skills development, and greater academic achievement. Behavioral and adjustment outcome data were obtained from two participating middle-school sites (intervention and comparison, involving 237 and 241 students, respectively) serving essentially equivalent urban communities. Results of the study revealed significant effects for academic achievement and behavior in terms of grade point average and teacher ratings that favored students at the intervention site. At this site, greater participation of parents in the intervention program was found to be positively related to improvement of the children in grade point average. No differential site-related changes in negative behavior were observed.