Accidental interruption of the hepatic artery or one of its principal branches is a feared surgical complication. Although vascular repair may be feasible, the injury is frequently so extensive that arterial reconstruction is not possible. In this situation, accurate knowledge of the consequences of ligation of the hepatic artery would be desirable. In the dog and other experimental animals, hepatic arterial ligation has been well tolerated if antibiotics are given. Similar information is not available for the human. The last comprehensive survey of accidental hepatic artery ligation in the human was by Graham and Cannell [1] in 1933. Their review indicated that a mortality of approximately 60 per cent could be expected. The present report documents five cases of injury to the common hepatic or right hepatic artery. Arterial reconstruction was impossible in four of the patients. In addition, the cases of ligation of the hepatic artery reported since 1933 have been compiled with particular attention to those patients treated during the antibiotic era. The results of this investigation suggest that ligation of the hepatic artery in the human is a less lethal complication than has been generally realized. CASE REPORTS CASE I A thirty-five year old man was operated on for subacute cholecystitis in May 1962. Jaundice had not been present. Cholecystectomy was difficult. During dissection of the neck of the gallbladder, the right hepatic artery was lacerated. (Fig. IA.) Efforts at arterial reconstruction led to further loss of vessel substance and the proximal and distal stumps of the right hepatic artery were ligated. It was noted that the right lobe (Fig. 2) was deeply cyanotic compared to the remainder of the liver. Drains were placed in the subhepatic space and the incision closed. For the first three postoperative days 6 gm. of chloromycetin and 4 gm. of erythromycin were given intravenously every twenty-four hours. From the third to the eighth postoperative days the antibiotic dose was reduced and given orally. The serum glutamic-oxalacetic acid transaminase (SGOT) rose abruptly within twenty-four hours of surgery (Fig. 3) and declined thereafter. The prothrombin time on the first, second and third postoperative days was 39, 29 and 25 per cent and then returned to normal. The bilirubin and alkaline phosphatase did not rise. (Fig. 3.) On the eighth postoperative day, fortyfive minute bromsulphalein retention was I per cent. The patient was discharged on the tenth postoperative day. Follow-up studies two and five weeks after surgery showed no abnormality of liver function. Comment-The injury to the right hepatic artery occurred in a typical location where the artery passes close to the neck of the gallbladder. The striking color change in the right lobe was considered an ominous sign. However, the only demonstrable consequence was a shortlived rise in SGOT and a similar prolongation of the prothrombin time. The liver was