The findings of a study of urban injury-producing traffic accidents in Adelaide, South Australia have been compared with the findings of a study of rural, injury-producing highway accidents in the U.S.A. The rural accidents had more front impacts, higher impact speeds, and more severe damage to the cars involved, than the urban accidents. In the rural accidents car occupants were injured more often and more severely than in the urban accidents. The head and lower limbs were injured most frequently in both groups of accidents. In urban accidents the door was the chief cause of injury to all body areas except the leg, due to the large number of side impacts. In rural accidents the windshield, steering wheel, instrument panel and ejection were the chief causes of injury. It is concluded that the differences between the two broad groups of accidents - urban and rural - must be considered when methods of alleviating injuries are being designed into the automobile. The three-point seat belt which restrains the upper torso is suggested as a most effective means of preventing injury in automobile accidents.