This document presents an evaluation of the effectiveness of the Growin' to Win Project, an after-school and summer program targeted at elementary and middle school aged youth at high risk of substance abuse and gang involvement. Growin' to Win is an expansion of a model latchkey program piloted at two Tacoma (Washington) schools in 1990. The program provides after-school and summer activities which encourage resistance to substance use; the improvement of self-esteem; and the development of academic, social, and life skills for students; and includes counseling and case management services as well as training for students, teachers, and staff in the areas of substance abuse prevention and intervention. Schools applied for participation in the program and were selected based on criteria that included student risk factors, and the expanded program has been implemented at three middle schools and one elementary school. The evaluation reports that, across three of the four sites, positive impact on the students' self-esteem was the most recognizable effect of the program. Findings suggest that self-esteem is a very important developmental factor for latchkey children and youth as it represents an evolving, cognitive-emotional attribute that is related to self-concept, school and peer relations, emotional well-being, physical self-perception, and resistance to substance use. Findings are presented for each of the four participating schools. Relevant forms are appended. (Author/NB)