Several criteria (frequency, hazardous use, drunkenness) were used to delineate four distinct groups and to analyse the relations between patterns of alcohol use and other health variables. In the 1993 Swiss Multicentre Adolescent Survey on Health, anonymous self-administered questionnaires were distributed to a national representative sample of in-school 15 to 20-year-old adolescents. Of the respondents, 25% answered a module targeting alcohol use (n = 2359) of whom 13% were totally abstinent, 55.1% were moderate drinkers (< or = 1 drink/week and < 3 times drunk), 21.7% were 'social' drinkers (> 3 times drunk and < twice driven when drunk) and 10.2% were 'problem drinkers' (> twice driven whilst drunk or > 1 drink/day). Differences between problem drinkers and the rest of the sample showed the former as being predominantly boys with an odds ratio (OR) of 6.3, having a higher lifetime prevalence rate of cannabis use (OR = 3.4), never using seat belts (OR = 2.5), having their family/peers more often involved in alcohol consumption (OR = 1.9), being predominantly apprentices (against high school pupils OR = 1.9), having cheated during courses (OR = 1.9), being a member of a gang (OR = 1.7), having stolen in a public area (OR = 1.7) and having considered suicide (OR = 1.8). Conclusion: Within the Swiss context, whereas moderate/occasional use of alcohol must be considered as part of an adolescents' development, regular use of alcohol, often associated with drunkenness and driving while drunk, is associated with various health hazards and problems. Preventive strategies should be built accordingly.