Substance use prevention studies published between 1980 and 1990 are reviewed for content, methodology and behavioral outcomes. Studies were classified based on the inclusion of 12 content areas: Information, Decision Making, Pledges, Values Clarification, Goal Setting, Stress Manage-ment, Self-Esteem, Resistance Skills Training, life Skills Training, Norm Setting, Assistance and Alternatives. Six groups of programs (Informa-tion/Values Clarification, Affective Education, Social Influence, Comprehensive, Alternatives and Incomplete programs) are identified. Reports are analyzed for two major threats to validity, selection bias and statistical power. Program groups generally have similar selection biases but have important differences in statistical power. Comprehensive and Social Influence programs are found to be most successful in preventing the onset of substance use.