Project S.T.O.P. is a conflict-resolution and peer-mediation training program for students and teachers. The Safe Harbor program addresses the victimization needs of students through a violence and victimization curriculum and counseling for victims and witnesses of violence. Four New York City middle schools participated in the research. One school had only the S.T.O.P. program, and three schools had both programs. Evaluation data were collected on 2,252 students from February 1993 until June 1994. Data were collected on students' knowledge, attitudes, and behavior, as well as on school climate, violence and victimization rates, and school incident report and disciplinary actions. The data were collected at four points in time. The evaluation found that the impact of both Project S.T.O.P. and Safe Harbor on attitudes toward violence and victimization is strong. The Safe Harbor directly impacts retaliatory attitudes, diminishing students' belief that violent retaliation is necessary in response to threats or perceived wrongs. Students exposed to both the Safe Harbor and Project S.T.O.P. are less likely to believe that respect is gained through violence. Students exposed primarily to Project S.T.O.P. are more knowledgeable about rape and sexual assault issues and also feel less helpless in response to violence and victimization.