The ideal system for management of trauma remains controversial, especially in respect of prehospital care and regionalisation of trauma-care delivery. To explore these issues, we compare two differing trauma systems--in the USA the focus is on the trauma centre, with a lesser emphasis on prehospital care, whereas in France there is more emphasis on prehospital care coordinated by the Service d'Aide Médicale Urgente. We describe the historical developments, current structure, and major controversies with regard to trauma-care delivery in the two countries. Comparative evidence on the effectiveness of the two systems was obtained through a structured review of databases, but very little evidence permits direct comparison of outcomes across the two systems. Crude injury mortality rates and fatality rates from motor-vehicle accidents (crashes in US usage) are higher in France than in the USA, although adjustment for potential confounders is difficult. Adjusted mortality rates suggest equivalent outcomes among patients who survive to hospital, although these data are confounded by the lack of a contemporaneous comparator population. There are differences in the American and French trauma systems that might translate into measurable differences in trauma-related mortality. However, the lack of data to allow comparison of outcomes between countries significantly impedes the identification and implementation of components of a trauma system that are effective and the discarding of those that offer little benefit.