Within a 3-year period, from 1980 to 1982, 1124 sports injuries of children aged 6-15 years were treated in the Turku University Central Hospital casualty department. Two-thirds (69%) of the injuries were sustained by boys. Sports injuries represented 21% of the diagnoses related to accidents in this age group. Half of the sports accidents occurred during the 4 winter months. Boys were injured most commonly in ice hockey (36%) and football (20%) and girls in skating (18%) and riding (18%). One quarter (26%) of the injuries were located in the head and neck, 36% in the upper extremities, 33% in the lower limbs, and 4% in the trunk. The most common types of injuries were fractures (26%), sprains and strains (24%), contusions (22%) and wounds (17%). The proportional occurrence of fractures increased with age in boys (P less than 0.001) and decreased in girls (P less than 0.001), luxations (P less than 0.05) and sprains (P less than 0.001) increased with age in girls; skull injuries (P less than 0.01) and contusions and wounds (P less than 0.001) decreased in boys. Girls had more sprains (P less than 0.001) but fewer contusions and wounds (P less than 0.001). Most of the injuries were mild; 9% of the cases were hospitalized. Minor surgery was performed in 16% and reconstructive surgery in 2% of all injuries. About 70% of the injuries occurred in nonorganized sports.