This report presents the methodology and first results of an in-depth study on head and neck injury mechanisms in victims of traffic accidents. Medical data on these injuries were obtained in detail from patients whose accidents were simultaneously studied by an accident investigation team, thus enabling satisfactory correlation between the biomedical and the biomechanical facts in a prospectively designed investigation. The kinematics and body responses of the accident victims were estimated by the application of the Crash Victim Simulator — Three Dimensional Model (CVS—3D). Results of the simulation indicate that the CVS-3D model provides excellent insight into the kinematics of occupants during crashes. Calculated values of head linear and angular accelerations were in the range expected and the ability to calculate neck forces and moments significantly adds to the understanding of neck injury mechanisms in accident victims.