In November 1982, epidemiologic data were collected in a unique, large scale, population-based survey on sports injuries in school-aged children living in Holland. A total of 7,468 pupils, aged 8 to 17, completed questionnaires covering a retrospective period of 6 weeks. Seven hundred ninety-one sports injuries were registered, amounting to an incidence of 10.6 sports injuries per 100 participants. In 31% of the cases, medical consultation was needed. Injuries incurred during the study period caused 36% of the children to miss one or more physical education classes and caused 6% to miss school for at least 1 day. Contusions and sprains were the most common lesions (77%). Three of four injuries involved the lower extremity, in particular the ankle. Sixty-two percent of all the injuries occurred in organized sports, 21% in physical education classes, and 17% in unsupervised sports activities. The highest injury rates were found in basketball and field hockey. In this study population, 15 and 16-year-old boys who had a high sports activity index and played team sports, particularly contact team sports, formed a high risk group.