The research concerning relative and independent influences of family and peers upon adolescent drug use is reviewed. Although conflict between family and adolescents is one of the oldest, most predictable, and-in Western society-probably least avoidable of developmental conflicts, the sharp focus upon this conflict in the context of adolescent drug use is a more recent development. As interest and concern regarding adolescent drug use has grown, so has the research seeking to explain this behavior. Much of this research has focused upon the role of family and peer influence. After a brief review of the theories which support either the greater impact of family or peer influence on adolescent behavior, a more specific review of the literature concerning the role of these influences on adolescent drug use is presented. The outline of this presentation is derived from Kandel's theory of stages of drug use. Finally, a summary of research findings and specific suggestions for future research are made.