Waves I and III of the National Longitudinal Study of Adolescent Health (Add Health) were used to test the contributions of alcohol, tobacco, marijuana, cocaine, LSD, PCP, and other illicit drugs to violence in early adulthood (e.g., took part in a gang fight, pulled a knife or gun, used a weapon in a fight, used a weapon to get something). The two main hypotheses were that well-known, non-substance abuse risk factors for violence in adolescence (e.g., gender, race/ethnicity, poverty, adolescent violence, school failure) would continue to elevate the risk for violence in early adulthood. Furthermore, substance use in early adulthood would eclipse the contribution of substance use in adolescence, thus increasing the risk for early adult violence. Results supported both hypotheses. Substance use in adolescence may not have a lasting influence on adult violence. In addition, the risk for early adult violence may be subject to contemporaneous influences of substance use as well as historical and contemporaneous non-substance use risk factors. (Contains 5 tables.)