Although community psychologists and prevention specialists view schools as the ideal vehicle for delinquency programs for children, few examples of effective school-based prevention programs are available. Delinquency prevention program developers view common school practices as contributing causes of delinquency, making school change a major target of prevention efforts. This paper discusses the issues in implementing and sustaining organizational change in schools to prevent delinquency. The first step in school change is to analyze the social system of the school by reviewing the school's program and change process, principal leadership and teacher involvement, and program integrity and adaptation. The second step is to analyze program implementation in regard to these basic issues of organizational change. A brief outline is presented of the history and program of the Delinquency Prevention Research and Development Project. Actual problems faced in managing prevention programs are discussed. Anecdotal evidence from experience with prevention efforts in seven cities in the United States is presented for the purpose of clarifying the basic dilemmas of changing schools to prevent delinquency. Conclusions from these attempts to change the social conditions of schools are offered, showing that until the means of effectively implementing prevention programs in schools can be derived, the potential for school-based prevention will remain unrealized. (Author/BL)