Premature autonomy describes a developmental dynamic where parents of high-risk adolescents reduce their involvement and guidance when confronted with challenges of problem behaviour and the influence of deviant friendships. This dynamic was tested on the sample of Oregon Youth Study boys (N=206), whose family management practices and friendships were observed on videotaped interaction tasks. Latent growth curve models were used to examine longitudinal trends between deviant friendship interactions and family management. Direct observations of deviant friendship process at age 14 were associated with degradation in family management during adolescence. A comparison of antisocial and well-adjusted boys clarified that parents of antisocial boys (started early and persisted) decreased family management around puberty, in comparison to parents of well-adjusted boys who maintained high levels of family management through adolescence. In predicting late adolescent problem behaviour, there was a statistically reliable interaction between family management degradation and deviant peer involvement in adolescence in support of the premature autonomy hypothesis. Adolescent males involved in deviant friendships, and whose parents decreased their family management, were most likely to use marijuana and commit antisocial acts at age 18. The implications for interventions that target adolescents are discussed.