From 2003 to 2006 the KiGGS Baseline Study was conducted, including a clustered random sample of 167 sample points and 17,641 children and adolescents from 0 to 17 years, as well as their parents in 167 sample points. The children and adolescents were medically and physically examined, and their parents answered questions about physical, psychological and social aspects of their children's health, as did, from 11 years on, the children and adolescents themselves. Within the framework of the nationwide health monitoring at the Robert Koch Institute, the KiGGS study is being continued as a prospective cohort study with an interval of approximately 5 years between follow-ups. The study sample will be cross-sectionally refilled with younger age groups at each time of measurement. The assessment of the KiGGS core study follows a core indicator concept, which is modularly complemented by external scientific cooperation partners. The field work of the first wave (KiGGS Wave 1), a telephone survey, will continue until June 2012. The second follow-up (KiGGS Wave 2) will again combine examinations and interviews, starting in 2013. On the basis of the nationally representative KiGGS data, important questions about health policy can be answered, such as trends and trajectories of health. Important results are expected, among others concerning trends in overweight and obesity, the incidence of atopic diseases, and the persistency or remission of psychopathological symptoms and disorders.