ABSTRACT: BACKGROUND: Research undertaken in developing countries has assessed discrepancies in police reporting of Road Traffic Injury (RTI) for urban settings only. The objective of this study was to assess differences in RTI reporting across police, ambulance, and hospital Emergency Department (ED) datasets on an interurban road section in Pakistan. METHODS: The study setting was the 196-km long Karachi-Hala road section. RTIs reported to the police, Edhi Ambulance Service (EAS), and five hospital EDs in Karachi during 2008 (Jan to Dec) were compared in terms of road user involved (pedestrians, motorcyclists, four-wheeled vehicle occupants) and outcome (died or injured). Further, records from these data were matched to assess ascertainment of traffic injuries and deaths by the three datasets. RESULTS: A total of 143 RTIs were reported to the police, 531 to EAS, and 661 to hospital EDs. Fatality per hundred traffic injuries was twice as high in police records (19 per 100 RTIs) than in ambulance (10 per 100 RTIs) and hospital ED records (9 per 100 RTIs). Pedestrian and motorcyclist involvement per hundred traffic injuries was lower in police records (8 per 100 RTIs) than in ambulance (17 per 100 RTIs) and hospital ED records (43 per 100 RTIs). Of the 119 deaths independently identified after matching, police recorded 22.6%, EAS 46.2%, and hospital ED 50.4%. Similarly, police data accounted for 10.6%, EAS 43.5%, and hospital ED 54.9% of the 1 095 independently identified injured patients. CONCLUSIONS: Police reporting, particularly of non-fatal RTIs and those involving vulnerable road users, should be improved in Pakistan.