Book excerpt: This report is the first major presentation of the international data from the 2001/2002 HBSC survey. The survey covered the physical, emotional and psychological aspects of health, and the influences of the family, schools and peers on young people aged 11, 13 and 15 years in 35 countries and regions in the WHO European Region and North America. The main body of the report gives comprehensive cross-national data on health and well-being, smoking, alcohol consumption, physical activity and sedentary behaviour, eating habits and body image, oral health, bullying and fighting, injuries and, for the first time, cannabis use and sexual health. Other chapters describe the contexts of young peoples health - socioeconomic inequality, puberty, relationships with family, peers, and schools - and discuss the implications of the surveys main findings for the future development of policies and programmes.