Family context has been identified as a central domain in the study of delinquency, particularly during early childhood. As youth enter adolescence peer associations become a much stronger influence. Using a sample of preadolescent youth, this research examines the effect of family and peer relationships on delinquency. Specifically, path analysis is used to test the effects of family structure, parental supervision, and parental attachment on serious delinquent behavior to determine if a youth's family life has a unique effect on serious delinquent behavior, or if familial relationships are mediated by peer associations. Findings suggest that parental variables are indirectly related to subsequent, serious delinquency, whereas delinquent peer association exerts a strong, direct effect. The study offers insight into the roles that a youth's family life and peer associations play in explaining delinquent behavior. In addition, the findings highlight the need for interventions that encourage pro-social relationships among youth.