A finite element model of a mid-size adult occupant has been developed in order to estimate overall injuries in traffic accident situations. Bones, ligaments, tendons, flesh, and skin are modeled using more than 80,000 elements. Several simulations were performed to validate impact responses of each body part. Detailed models of the head/face, shoulder, and individual internal organs have been also developed for more detailed analysis. The human model was used together with a model of a vehicle's internal structure to simulate a real-world accident situation and the simulations successfully reproduced gross motions and multiple injuries of an occupant.