Trends in official arrest and juvenile court statistics parallel statistics on juvenile alcohol and drug use reported in national surveys. A self-report survey of approximately 3,000 students in grades 7-12 in 7 midwestern communities shows a significant correlation between reported substance use and reported delinquent behaviors of varying severity. Other studies also indicate that substance use and delinquent behaviors are closely related, but none of the studies establishes that these variable sets cause one another. Findings suggest that delinquency and drug use are related through their common association with another set of social factors. Both drug and delinquent behavior are negatively related to strong, intact families with good parental supervision; religious ties; and good school performances and experiences. The single best predictor of juvenile behavior, conforming or delinquent, however, is the behavior of close friends. 5 tables, 4 figures, and 28 references.