To determine whether anesthesiologists, because of prolonged exposure to halothane or other inhalational anesthetics, might have higher death rates from all causes, from cancer, and from hepatic or renal disease than other physicians, the mortality rates of male and female members of the American Society of Anesthesiologists (ASA) for the period 1954 to 1976 were examined. Records of all physicians on ASA membership lists in 1954, 1959, 1967 and 1976 were obtained. All members, including life members, retired members and those who had stopped paying dues, were traced. Of the 637 deaths between 1954 and 1976 in male anesthesiologists, death certificates were obtained for 610. Mortality from all causes in those members who were accredited prior to 1960 was 84 per cent of the expected death rate of all physicians. Among male members of record in 1967, it was 93 per cent of the expected rate. There was no suggestion of an increased rate of cancer or hepatic or renal disease. There was a high suicide rate in members less than 55 years old. The overall mortality rate for the relatively small group (n = 66) of female anesthesiologists was 75 to 85 per cent of that expected for all female physicians.