BACKGROUND: Except for that of skilled and professional personnel, labour migration has practically ceased in Europe since the mid-1970s, and many of those who migrated as single males now have families in host countries. In Switzerland, among school-attending adolescents both of whose parents were born outside the country, some three quarters are children of labour migrants. Our hypothesis is that these adolescents present particular adjustment difficulties attributable to low socio-economic status and double cultural affinity. OBJECTIVE: To compare Swiss and labour-migrant adolescents in attitudes towards health risks, psychological adjustment and family relationships. METHOD: As part of the Swiss Multicentric Adolescent Survey on Health, an anonymous self-administered questionnaire was distributed in school classes among a national representative sample of 9300 fifteen- to twenty-year-olds. The subsample of labour-migrant youth includes 1200 adolescents both of whose parents are from Italy, Spain, Portugal, Turkey or former Yugoslavia. RESULTS: Bivariate analyses show significant differences between Swiss and labour-migrant adolescents in health concepts and health behaviour (notably, sexual behaviour and substance use), general well-being and family relationships. Only alcohol consumption and drink-driving behaviour place migrant adolescents at a lower risk than their Swiss peers. When sociodemographic variables are controlled in multivariate analysis, less favourable perceptions of the future, more marks risk behaviours, symptoms of depression, and difficult relationships with parents all appear to be strongly associated with migrant status. CONCLUSION: The findings of this study reflect the negative effects of lack of social stability and of clear opportunities and positive perspectives on the health and psychosocial adjustment of migrant adolescents.