Accidental mechanical asphyxia is an unusual cause of death. In reviewing 73 cases occurring during a 10-year-period in Sweden, young boys and elderly women seemed to be most prone to this type of fatality. A striking number of victims had deliberately put a noose-like structure around the neck, and yet another group became entangled in some part of their clothing. Thoracic immobilization was seen in a number of cases, also involving work-related accidents. Hospitalized patients, asphyxiophilics and inebriated victims represent other risk groups. A case involving the use of a helmet is reported in view of the growing frequency with which Swedish children use bicycle helmets. The material contains only a few cases where the victim was not alone at the time of the accident, and it seems plausible that supervision could have prevented many of the reported fatalities. Public knowledge of accident mechanisms may increase the awareness of hazardous situations and activities. Spreading of the medical examiner's knowledge may thus form a basis for accident prevention.