In this paper, frontal motor vehicle pedestrian collisions are classified according to post-impact pedestrian kinematics observed in real world vehicle vs. pedestrian accidents. Results from in-depth pedestrian accident investigations ** provide the medico-engineering basis for this study. It was found that impact-induced pedestrian motion is influenced by the relative configuration of the vehicle and pedestrian at impact as well as the vehicle's impact speed and deceleration rate. Injury patterns were found to be dependent on the trajectory type in addition to impact severity and characteristics of the vehicle and roadway.Five basic kinematic trajectories have been identified for frontal collision cases and are described as: wrap, forward projection, fender vault, roof vault, and somersault. Pedestrian injury patterns are analyzed for each of the trajectory types; an injury risk index is defined; and the associated injury risks are compared.It is hoped that classification of the characteristic injury patterns and trajectories can facilitate vehicle design improvements to reduce pedestrian injury severity.