A 5-year federally funded substance abuse prevention program targeted 426 high risk middle-school youth from 4 school districts in Nassau County, New York. Combining a child-centered model with a systemic approach, the program's goal was to prevent or delay the onset of alcohol and other drug use. High-risk youth were identified by school counselors, administrators, and teachers based on indicators such as: discrepancy between ability and performance, excessive absence, and history of behavior problems. A cluster of 8 to 10 high risk grade seven students interacted daily with a teacher-mentor throughout their middle school experience. Program initiatives sought to: (1) increase skills of mentors in four middle schools; (2) increase parental involvement; (3) improve youths' self esteem, relationships, and drug, alcohol, and tobacco refusal skills; and (4) strengthen youths' study skills and academic achievement. A pretest-posttest comparison group evaluation found positive outcomes. The teacher-mentor component was the program's major strength. Future studies should focus greater emphasis on qualitative evaluation useful in documenting some of the real but elusive changes which were not captured by the quantitative data. (JBJ)