For the most part, prevention programs designed to reduce alcohol problems have not been notably successful at the community, State, or national levels. This results primarily from two factors. First, the development of alcohol-problem prevention programs and policies is rarely based on scientific evidence. Many prevention programs are funded by public and private sources with little scientific evidence of potential effectiveness. This lack of a scientific basis for prevention activities is not due to the lack of scientific evidence. In the area of alcohol policy alone, there is a substantial research literature. The problem is the lack of desire and demand for scientific justification for a specific prevention activity that uses human and monetary resources. Instead, most efforts in both alcohol-problem and drug-use prevention are designed so as to provide personal satisfaction, and in some cases, public attention for the professionals and staff involved. The most convincing evidence of the effectiveness of a proposed prevention activity would be prior scientific studies (evaluations) that are replicated in multiple conditions and consistently show the effectiveness of the proposed prevention activity or policy. Short of this standard, the next level of evidence would come from promising scientific research (perhaps not substantially replicated) and theory that supports the potential of the prevention activity to be effective. The lowest minimum level of support should be a clear statement of the theory or conceptual model on which the prevention effort is based. The second priority for drug-use and alcohol-problem prevention programs for the year 2000 is consideration of the cost of prevention efforts as measured against demonstrated effectiveness in reducing alcohol-related problems. 7 references