AIMS: To assess the association between drinking behaviour among adolescents with both immigrant and native backgrounds with aspects of acculturation. DESIGN: Cross-sectional school survey among 15-16 year olds. SETTING AND PARTICIPANTS: All students, a total of 8361, in 10th grade during spring 2000 and 2001 in Oslo, Norway with response rate 88.3%. The sample consisted of 1213 students with an immigrant background and 4627 students with a Norwegian background. MEASUREMENTS: Indicators of the length of the acculturation process were assessed as first versus second generation and in terms of length of stay in Norway. The proportion of Muslim students in school was an indicator of social environment 'dryness'. Drinking behaviour was assessed as drinking alcohol ever, drinking frequency and intoxication frequency. FINDINGS: A smaller proportion of immigrant students were current drinkers, frequent drinkers and drank to intoxication compared with adolescents with a Norwegian background. Adjusted two-level analyses showed that alcohol drinking was less common among immigrant students with a short stay in Norway and with a large proportion of Muslim students in school. In those with a Norwegian background there was a larger proportion of abstainers, and those who drank did so less frequently and were less frequently intoxicated the larger the proportion of Muslim students there was in their school. CONCLUSION: Drinking behaviour among adolescents in a multicultural and heterogeneous society seems to reflect a bi-directional acculturation process where the majority population tend to adapt to the behaviours of the immigrant population which in turn, to a varying degree, tends to adapt to the behaviour of the majority population.