In every country in the world, pedestrians are being killed in traffic accidents. This serious social problem needs to be dealt with as soon as possible. Most pedestrian fatalities are due to the forces transmitted to the head from contact with vehicle bodies. To reduce the number of deaths in such accidents, it is necessary to study how to protect pedestrian’s head. To investigate ways to protect the head, the locations of head contact with the vehicle body and the corresponding velocities need to be studied. This paper describes our tests that used a full scale sled to determine how the orientation of pedestrians, shape of the front bumper and hood edge, and energy absorbing characteristics of those parts affect the head injuries of adult and child pedestrians. Computer simulation was also used in some cases to check the results of the actual tests. Prior to our study it was thought that bumper lead and hood height had individual effects on pedestrian injuries, but it was ascertained, as a result of our study, that these two conditions are interactive which leads to a more complex injury mechanism.