This paper examines the distribution of injuries to belted occupants involved in frontal crashes, using data from the National Accident Sampling System. Similar studies of data from Canada, Britain, and Federal Republic of Germany are summarized. The studies are consistent in showing that head and chest injuries continue to be the most harmful to belted occupants. For restrained drivers, liver injuries contribute a significant level of harm among chest/abdominal injuries. Other significant lesions of nearly equal weight are arterial, heart, lung/pulmonary, skeletal, and crushing injuries. Brain injuries are by far the most harmful head injury, followed by skull fracture and facial fracture. The diverse distribution of injuries, and the wide variation in occupant sizes and injury tolerances are significant considerations in optimizing restraint systems for maximum injury reduction in real crashes.Injury patterns for air bag restraints are also examined, based upon test data and field data. To date the air bags in service are performing as designed, and no patterns of serious injuries have emerged.