This 17-year prospective study applied a social-developmental lens to the challenge of distinguishing predictors of adolescent-era substance use from predictors of longer term adult substance use problems. A diverse community sample of 168 individuals was repeatedly assessed from age 13 to age 30 using test, self-, parent-, and peer-report methods. As hypothesized, substance use within adolescence was linked to a range of likely transient social and developmental factors that are particularly salient during the adolescent era, including popularity with peers, peer substance use, parent–adolescent conflict, and broader patterns of deviant behavior. Substance abuse problems at ages 27–30 were best predicted, even after accounting for levels of substance use in adolescence, by adolescent-era markers of underlying deficits, including lack of social skills and poor self-concept. The factors that best predicted levels of adolescent-era substance use were not generally predictive of adult substance abuse problems in multivariate models (either with or without accounting for baseline levels of use). Results are interpreted as suggesting that recognizing the developmental nature of adolescent-era substance use may be crucial to distinguishing factors that predict socially driven and/or relatively transient use during adolescence from factors that predict long-term problems with substance abuse that extend well into adulthood.