Past research examining the influence of parenting styles on adolescent externalizing behaviors and substance use has left questions with regard to whether there is a relation between parental social support and adolescent externalizing symptomatology. This study examined the influence of parental control and social support on adolescent externalizing symptoms and substance use using a longitudinal design, and attempted to remedy limitations of past research. Data from a longitudinal study of adolescents (N=454) and their parents were used. Approximately half of the adolescents had at least one parent who met lifetime diagnosis of alcohol abuse or dependence. Parent and adolescent reports of symptomatology and adolescent reports of parenting were submitted to multiple regression and cross-lagged panel correlation analyses. Results showed that parental social support and control were generally negatively related to adolescent externalizing symptoms, alcohol use, and illicit substance use. Additionally, results showed a quadratic relation between parental control and adolescent externalizing symptoms and illicit substance use, but not for adolescent alcohol use. Finally, the results indicated that the assumed direction of causality, from parenting to negative child outcomes, may be incorrect. Future research should examine the mediators through which parental support and control influence adolescent problem behaviors. (Author/ABL)