The main goal of this study is to investigate social influences of adolescent smoking and drinking. These social influences include social motives, parental attitudes, communal mastery and peers' substance use patterns. Literature suggests that communal mastery (as a form of social competence) may be related to adolescent substance use. In addition, gender differences may be hypothesized in the social influences of adolescent substance use. Data were collected in a middle and high school student population (N = 634, 50.6% males, age range: 11-19, mean: 15.6, S.D.: 2.0) in Szeged, Hungary. The instruments contained questions on sociodemographics, smoking and drinking, social influences, social motives, and communal mastery. Results showed that high levels of communal mastery was an important protective factor against adolescent boys' smoking and drinking. For girls, communal mastery did not play such a role. The role of social motives, friends' and best friend's substance use and parental approval also were justified.