BACKGROUND: Behavioral factors such as (excessive) alcohol consumption play a major role in the explanation of social inequalities in health. The unequal distribution of health risk behaviors among socio-economic groups has important consequences for both the current and future health status of the younger generation. However, little is known about socio-economic differences in unhealthy lifestyles during adolescence. The purpose of the present study is to investigate socio-economic differences in adolescent drinking behaviour among 11-15 year old adolescents in Europe and North America. METHODS: Data was obtained from the Health Behaviour in School-aged Children (HBSC) study 2001/02, a cross-national survey conducted in collaboration with the World Health Organization. The present analysis is based on 69249 male and 73619 female students from 28 countries. The effect of parental occupation and family affluence on episodes of drunkenness was assessed using separate logistic regression models controlling for age. RESULTS: Socio-economic circumstances of the family had only a limited effect on repeated drunkenness in adolescence. For girls only in one out of 28 countries a significant association between family affluence and repeated drunkenness was observed, while boys from low and/or medium affluent families in nine countries faced a lower risk of drunkenness than boys from more affluent families. Regarding parental occupation, significant differences in episodes of drunkenness were found in nine countries for boys and in six countries for girls. Compared to family affluence, which was positively related to risk of drunkenness, a decreasing occupational status predicted an increasing risk of drunkenness. This pattern was identified within a number of countries, most noticeably for boys. CONCLUSION: Parental socio-economic status is only of limited importance for episodes of drunkenness in early adolescence, and this very limited role seems to apply for girls more than for boys and for parental occupation more than family affluence. For future studies it might be important to look at the effects of socio-economic status within the context of other peer, family and school related factors in order to assess to what extent those factors might mediate the effects of social class background.