Tests were conducted to provide information on the mechanics of child restraint with a five-point harness system. For anatomical reasons, the juvenile chimpanzee was chosen as the best approximation to the human child. Sedated juvenile male chimpanzees withstood frontal deceleration tests in a five-point harness at crash speeds of 32.2, 40.2, and 48.3 km/h (20, 25, and 30 mph) without skeletal bone fractures or evidence of soft tissue injury. Injury assessment was by X-ray and blood serum enzyme analysis as well as ECG readings and post-test observations of the animals' behavior. While this animal model does not fully guarantee the identical performance of a five-point harness system with humans, these results support the opinion that the protection offered a child occupant in a five-point system is comparable to that available to adult passengers in conventional automotive restraint systems.