The analysis of the accuracy of prediction that individuals were more likely to become violent when they consumed alcohol rested on a sample of 714 individuals. The participants were matched pairs of individuals, one predicted to be violent and the other predicted not to be violent. The research followed the predicted and comparison individuals in the community through interviews over a 6-month follow-up period. The interviews collected information about changes in social networks, drug and alcohol use, work, symptoms, treatment, and violent incidents. Results indicated that mental health professionals do not distinguish well between individuals who are likely to become violent during periods in which they drink from those who are not. The medical health professionals’ predictions appeared more descriptive of the drinking behavior of a high-risk group than predictive of alcohol-related violent incidents. Thus, even when their apparent decisional processes are considered in tests of accuracy, mental health professionals’ predictions of violence are only moderately more accurate than chance. Further research is recommended. Tables and 76 references (Author abstract modified)