There exist two different methods to investigate the injury mechanisms and the tolerance levels, either sled tests or real road traffic accidents. Sled tests conducted at the University of Heidelberg and real accident cases examined by the University of Hannover were compared. The impact conditions of the Heidelberg sled tests were frontal collisions, with an impact velocity (Δv) of 50 km/h and decelerations of 10 g's to 20 g's. Twenty-nine tests with 3-point-belt protected cadavers in the age range 19 to 65 years were included in the Heidelberg collective. The Hannover sample contained 24 frontal accident cases (30 occupants) with a 100% overlap of the car front with the same Δv and average car deceleration range similar as the sled tests, the passenger compartment was only minimal intruded. Three-point belt protected drivers and front passengers in the age range of 18 to 71 years were included in the sample.The injury pattern and injury severity were found in the cadavers through autopsy, while for the traffic accident sample clinical findings with detailed description of all injuries were stated.In 6 sled tests no rib fractures were observed and in 10 sled tests thorax AIS 2 (2-3 rib fractures, or one sternum fracture) were found. The most fractures were infractions, which means pains in the real accident situation. In 5 cases each one with 9 to 17 rib fractures were observed. The most cases show a spinal AIS 1 and 2, which means, strains and ligamental lacerations.In the real accident sample all the injury degrees of AIS 0 to AIS 6 were found. The most frequent injuries were abrasions and haematomas (AIS 1) but in some cases fractures of the face, rib and extremities were observed.The results show, that real accidents could be compared with sled tests if accident conditions, i.e. severity and impact direction were taken into account. The mechanisms of the injuries in real cases will be discussed with sled test results.