During a 5-month period a study was made of motor vehicle occupants presenting at an Accident and Emergency department following an accident. Records were made of the incidence of neck injuries in relation to the presence of head restraints and the use of seat belts. There was a slight reduction in injuries when a head restraint was fitted but this difference did not achieve statistical significance. The incidence of neck injury was not increased if a seat belt was worn. It may be that the reason for the failure of head restraints to afford the expected protection is their inappropriate design and lack of adequate adjustability.