The purpose of the study was to assess the one-year incidence of traffic injuries among residents 14 years of age and older, as well as their distribution by age, gender, road-user category, place of occurrence, and severity of the injury. A one-year survey was conducted in the emergency departments in Barcelona, Spain, based on a multistage cluster sampling of 8-hour shifts stratified by time of the year, day of the week, and time of day. All death certificates (E810-829) for residents in this same age group were also included. Information was collected prospectively in EDs by specially trained nonstaff interviewers. The baseline estimate of incidence of injuries was 1,037 per 100,000 population. The highest incidence was for ages 20-24 and 15-20 years. Incidence rank-ordered road-use categories were: motorbike occupants, passenger car occupants and pedestrians, the first category accounting for almost half of all injuries. There were 108 admissions and 15 deaths per 1,000 incident cases. Case-admissions ratios increased with age and were highest for pedestrians, who also accounted for the highest case-fatality ratios and ISS mean scores. The study offers the first description of the epidemiology of traffic injuries in a large southern-European city. Although overall age and gender incidence patterns were similar to those described in other western countries, the striking contribution of motorcycle injuries has not been previously pointed out, underscoring the urgent need to implement effective strategies to reduce injury risk associated with motorcycles and mopeds.