Introduction: Self rated health, in adult population, is strongly associated with mortality and life expectancy. In younger people this association is less evident, but it may anticipate a similar risk in adult life. Our research, based on the HBSC (Health Behaviour in School-Aged Children) International collaboration, contributes to deepen the knowledge in this field by monitoring adolescents' health through a multinational survey involving 29 European countries, plus North America (Canada and USA) and Israel. Methods: Following an established methodology, the HBSC survey has elaborated a questionnaire on health and health behaviour, filled in by a representative national sample of 11-, 13-and 15-year-old boys and girls. The sample is constituted of more than 160,000 subjects interviewed during the 2001/2002 survey. Reported symptoms and self-rated health have been analysed by sex and age and through the different countries. Results: Girls resulted to have a poorer perception of their health, with respect to males, at all ages and in all countries (Overall OR = 1.70, 95% CI: 1.66-1.76). Age increases this risk both for males and females, with an average increase of 32% (95% CI: 29-34%) per year in the age-range 11-15. The situation is similar for reported symptoms, with an overall OR of 1.81 (95% CI: 1.77-1.85) for females of reporting three or more symptoms at least once a week; also this risk increases of 26% (95% CI: 24-27%) per year during the pre-adolescence phase. In both cases it could be shown a significant interaction effect between age and gender: OR = 1.19 (CI: 1.15-1.23) for perceived health and OR = 1.26 (CI: 1.23-1.29) for reported symptoms in females with respect to males. Conclusions: Even if adolescence is described as the healthiest period of life, a consistent minority of young people perceive and report a poor health and a high number of symptoms. Females are constantly in a worse position than males and older age groups are worse than younger ones.