In health surveys as well as on European level little information exists about the perceived health, i.e. quality of life, of children and adolescents in the community. The project aims at a co-operative European development of standardised screening instruments for children's quality of life, which will be used in representative national and European health surveys. It also aims at identifying children at risk interims of their subjective health to suggest early intervention possibilities. In addition the project addresses the impact of chronic health conditions on quality of life in children/adolescents including social and behavioural factors as determinants perceived health. After the instrument development phase, the standardised measures of Sol and their determinants will be used in representative population surveys in the participating countries and will be implemented and evaluated in national health services.