From 1 April 1991 to 31 March 1993 the Royal London Hospital Helicopter Emergency Medical Service (HEMS) attended 737 road traffic accidents, 90 (12 per cent) of which involved entrapments. Nine casualties (10 per cent) died, of which five died at the scene. Thirty-two patients with a median ISS 17 (range 1-59) were transported by helicopter to the Royal London Hospital. Of these, four subsequently died in hospital. The median ISS of the non-survivors was 44 (range 24-59). The remaining 53 patients were transported to the nearest hospital. In 45 cases (50 per cent) patient extrication took longer than 30 min. The methods and standards for the release of trapped road traffic accident victims were reviewed to allow physicians a working understanding of Fire Service techniques. Entrapment rescue should create rapid access to the accident victim, allowing stabilization and release with minimum delay. Immediate and uncontrolled release of trapped victims is only indicated if there is immediate danger to life from the surroundings. We recommend a rigorous target of less than 30 min for the release of the casualty. To achieve this will require systematic extrication training for Fire Service crews and medical teams who are involved in immediate care.