The aim of this one-year investigation of school accidents is to obtain more knowledge for preventive work. In the age-group 7-19 years, 547 injuries were registered, mainly at three hospitals. The incidence rate was 25 per 1000 boys and 20 per 1000 girls per year. Most injuries occurred in intermediate and upper secondary school among boys and in upper school among girls. The relative risk of school injury compared with spare-time injury was 1.8 for boys and 2.6 for girls of compulsory school age. Most injuries occurred in sports area (boys: 34%, girls: 46%). The incidence of sports injuries showed no gender differences. The highest incidence rate was found in senior school girls. Twenty-five percent of all injuries were caused by other pupils, intentional violence being one important mechanism. Head injuries were more common among school injuries compared with spare-time injuries.