Since prisons are organized and limited mini-communities with structured activities, they provide an ideal structure for preventive work with alcohol and drug abuse. Such efforts must include the assessment of each inmate in terms of substance use, the role of drugs in the lifestyle of the inmate, and his willingness and capacity to change. Also, patterns of drug and alcohol use in the prisons as well as the sources for the substances must be determined. These assessments should be followed by the implementation of strategies of primary, secondary, and tertiary prevention. Primary prevention would target the prison population in general through the control of access to drugs, health education, and the promotion of healthful practices. Secondary prevention would target consumers who have already experienced symptoms or problems with alcohol or other drug use. This might involve the profiling of users, the detection of individual users, user supervision, and case management for appropriate treatment. Tertiary prevention would target a limited group of alcoholics or drug addicts with such programs as specialized intervention units, a prerelease program, and the coordination of treatment programs for parolees. 9 references