This article summarizes the types of community policies that have shown effects on decreasing youth drug use, the contribution of community organization to policy change, and finally, the role of policy change on maintaining-or institutionalizing-community-based prevention efforts. Two types of policy change are considered: those involving implementation and those related to applicable regulations. Implementation policies are those aimed at institutionalizing prevention programs, usually through raising funds, requiring standard implementation, and creating a formal non-profit organization to implement programs. Regulatory policies include all formal laws, regulations, and ordinances aimed directly at decreasing drug use, for example, regulations which enforce the monitoring of drug-free zones. Results of studies suggest that regulatory policies may show the most immediate effect on youth tobacco and alcohol use. Programmatic policies have the most potential for long-term effects on use. Community organization appears to stimulate change in both types of policy. As yet unresolved is whether policy change can subsequently contribute to long-term community prevention efforts. Recent research has identified several barriers to institutionalization of community prevention, including a) a lack of perceived empowerment by community leaders to continue prevention work; b) insufficient preparation of community leaders for adoption of evidence-based programs; c) the notion of continuing an ineffective approach because of the costs already "sunk;" and d) a general perception that no proscribed evidence-based approach will work because each community has its own unique needs. Furthermore, results suggest that policy change requires a two-to three-year commitment