This article summarizes the proceedings of a symposium, chaired by Peter Monti and cochaired by Tracy O'Leary, that was presented at the 2001 RSA Meeting in Montreal, Quebec. The aim of this symposium was to present data on group- and individual-based interventions for adolescent alcohol and substance abuse, with a discussion of the implications of research findings bearing on developmental considerations when working with adolescents and young adults. Elizabeth J. D'Amico, PhD, reviewed recent findings on adolescents' choice of type of substance abuse treatment. Jennifer L. Maggs, PhD, presented a developmental perspective on this issue. Tracy O'Leary, PhD, presented data on enhancing motivational interviewing with the presence of a supportive peer for college students cited for alcohol infractions. Mary E. Larimer, PhD, presented 1-year follow-up results of the Greeks 2000 Project, a 5-year longitudinal study designed to evaluate the efficacy of an alcohol abuse prevention program provided to college students who were entering a pledge class (first year) of Greek houses. Barbara McCrady, PhD, a noted expert on the treatment of couples for substance abuse problems, served as discussant.