Total population injury surveillance was implemented in a geographical area with a population of over 41,000. All accidents taking place over one year that required medical care were noted. A total of 4,926 were registered, for a rate of 118.9 per 1,000. They consisted of accidents in the home (35.0%), sports accidents (18.9%), accidents at work (13.7%), traffic accidents (12.8%), and "other" accidents (19.5%). Men were involved in 62.2%, and were overrepresented in all age groups but 70 years and over. The commonest cause of injury was falling (36.4%), followed by injuries due to falling objects or blows (17.7%), cutting or piercing objects (15.0%), and physical overexertion (12.9%). Half of the victims covered by health insurance were put on sick leave in connection with the accident, and 12.6% of these were admitted to the hospital. The age group 13-19 years, and also men 20-29 years of age, showed the highest accident rate. The risk of accident was four times the average in mining and quarry workers. The number of accidents per resident for people living in single-family houses was almost twice that for people living in flats, a phenomenon not previously reported. Sports caused many serious injuries. In some respects the accident pattern in this study differed from that in another, comparable study and from official statistics. The difference is especially great concerning the number of accidents in the home.