Detailed investigations of automobile crashes in which children under 10 years old were passengers were carried out. The purpose of this study was to investigate the injury patterns of restrained and unrestrained children and to assess the performance of child restraint systems in real world crashes. Crashes which occurred mainly in Washtenaw and Oakland counties of the state of Michigan were surveyed. A total of 348 vehicle crashes involving 494 children less than 10 years old were identified. Forty eight crashes involving 63 children were selected for in-depth investigation. 37% of the children in the investigated cases were restrained by an adult lap belt or a child restraint. It was found that only 4.7% of the children in the overall sample were restrained.Both adult seat belts and child restraints (when used) were found to be effective in reducing injuries in crashes. Head and facial injuries were found to be the most common form of injury to children. The vehicle interior contact points which produced some of these injuries were not covered by Federal Motor Vehicle Safety Standard 201 on occupant protection in interior impact, which specifies requirements for padded instrument panels and some other interior components.