During recent years the prevalence of family break-up has increased. Every third child growing up in Norway today may experience divorce among their parents. In this paper we try to illustrate to what extent experiencing divorce during childhood is related to subjective health and health behaviour in adolescence. The study is based on a self-administered questionnaire among 828 students in secondary schools in Førde (91% of all). Every fifth student reported experience of family break-up, and we compared this group with the rest concerning subjective health and health behaviour. We found significant differences in the disfavour of adolescents whose parents were divorced, with regard to both physical and emotional health complaints. We also demonstrated marked differences concerning health risk behaviour, especially smoking. The subjective assessment of wellbeing and performance in school were lower among adolescents with divorce experience. It is concluded that family break-up represents a major stressful event for children with marked health consequences in adolescence. Such consequences should be considered in plans for preventive health measures and health care for children and adolescents.