BACKGROUND: The phenomenon of repetitive injuries has been judged to be of limited importance in the public health context. A study was therefore initiated in order to analyse all types of single and repetitive injuries using a longitudinal approach. METHODS: Hospital care, medical costs and risk factors were examined for single and repetitive severe injuries. A cross-sectional survey with a 12-year follow-up was performed. Questionnaire information from a survey of a random sample of the adult population 20-89 years old in 1984 in Stockholm County were linked to the Swedish national inpatient and cause-of-death register up to 1996, inclusive. RESULTS: During the study period 13% of males and 15% of females were hospitalized or deceased as a result of injuries. Persons with three or more injuries comprise 19% of the injuries, but account for 63% of the total number of days of hospital care and medical costs. Injuries related to falls were most common among patients requiring hospital care. Factors such as high age, living alone, stroke earlier, and use of hypnotics and sedatives were especially associated with repetitive injuries. The risk factors for single and repetitive injuries covariate, but the size of the risk is overrepresented for stroke, drugs, self-reported injuries and living alone for two or more injuries. CONCLUSION: These results indicate that subjects with repetitive injuries, and with the observed risk factors for such injuries, should be given extra attention, both in policy and prevention, but also in integrated treatment programmes.