The purpose of this paper is to provide the beginning counselor with an overview of prevention concepts. Prevention is a relatively new emphasis in community efforts to stem the rising costs of substance abuse and other high-risk behaviors. The paper discusses agent, host, and environmental prevention models and how they relate to causal theories of addiction. It stresses that prevention strategies must relate to causal models of addictive behavior if they are to have any likelihood of making an impact. Target populations must be clearly identified, and risk and protective factors need to be accurately described. Prevention is important because it offers alternatives to treatment that is costly, available to a select few, and frequently not effective. Counselors play a critical role in prevention as they have the skills in interpersonal communication to facilitate problem solving, goal setting, and collaboration. They are in a position to advocate for system change and to model healthy behaviors to their clients, students, and members of the larger community. The role played by counselors in prevention work is described, and summaries of effective prevention programs are presented. Also included is a facilitator's manual which is a practical guide for teaching content through guided experiential projects. Four objectives are listed, and seven student exercises are provided. (Contains 36 references.) (MKA)