This paper examines the consistency of hospital and police reporting of outcomes of road traffic crashes using a database of linked police crash reports and trauma registry records. Criteria for inclusion into the trauma registry include trauma-related causes with subsequent stay of more than 24 h or death due to injuries. During the 1997 calendar year there were 497 cases of road-related injuries within the combined trauma registry of Sir Charles Gairdner and Fremantle Hospitals, of which only 82% had matching police records. Linkage rates were associated with gender, injury severity and the number of vehicles involved. Within the road user category, pedestrians were least likely to link. Of the linked records, police classification of injury severity was correct in 78% of cases. Male casualties were more likely to be correctly classified than females, after adjustment for related variables including injury severity. Correct classification of injury by police was also closely related to severity of injury. Identification and targeting of these groups of casualties is vital in refining the road-crash reporting system. Increased crash reporting and availability of data from these two sources will provide road authorities with more reliable measures of injury outcome.