From August 2004 to June 2005, the Robert Koch Institute conducted the fieldwork for the Schleswig-Holstein module of the German Health Interview and Examination Survey for Children and Adolescents (KiGGS). The KiGGS study is a nationwide representative survey of the health of children and adolescents aged 0 to 17 years. By increasing the sample size in the age group 11 to 17 years in Schleswig-Holstein, the module study generated information which is representative for this federal state. For this end, further 18 locations in this federal state were included in the module study in addition to the existing 5 study locations in Schleswig-Holstein and a study programme which was slightly reduced compared to the core survey was realised. A total of 1,931 subjects were examined in Schleswig-Holstein: 1,730 in the federal state module and 201 in the core survey. The participation rate was 69.5% in the module study. The percentage of quality-neutral drop-outs was 4.0%. The federal state module was funded by the Ministry of Social Welfare, Health, Family, Youth and Seniors of the Federal State of Schleswig-Holstein. The data collected were used for health reporting on a federal state level.