The authors of this study characterized the attributable mortality rate from anesthesia by examining the records of more than 33,000 patients receiving anesthesia during a 10-year period. Cases are categorized by the type of anesthesia given, the number of deaths recorded, and the characteristics of the patients and their indicated procedure. The authors conclude that the physical condition of patients relates most closely to the contribution of anesthesia to death. When deaths were related to the use of muscle relaxants, errors of omission or commission were always noted to be present.