Little information is available on the performance of child restraints in severe accidents;​ some has come from 'in-depth' studies of relatively few accidents and from less detailed investigations of a large number of accidents, many of them rather minor. For this reason, a study has been made of all fatalities to restrained children in Great Britain since 1972 from Police and Coroners' records. This paper describes the results of this study for children aged up to four years. Some accidents have been simulated by sled tests as an aid to understanding the mechanism of injury. In most cases, the severity of the accident was such that it was unlikely that an improved restraint design could have prevented the fatality. This report summarizes the cases studied and draws conclusions about the few cases where the protection afforded by the restraint was impaired.