This report describes five cases of hepatocellular injury following halothane anesthesia. Four patients had multiple exposures to the anesthetic. Three of the five died from submassive to massive liver cell necrosis. The two survivors developed jaundice and/or dark urine following each exposure to halothane; liver biopsy in one showed centrilobular and linear areas of necrosis. Fever, anorexia, nausea, vomiting, abdominal pain and jaundice were present in all cases. In the two survivors the prothrombin time was less than 20 seconds throughout the course of the disease, whereas in the three who died the prothrombin time was more than 20 seconds from the onset. The English literature to the end of 1971 is reviewed. Approximately 600 cases of halothane-related hepatitis have been reported