Because the hepatic artery provides the only blood supply to the biliary tree of a liver allograft, posttransplantation arterial occlusion may result in a biliary complication. Cholangiograms were reviewed retrospectively in 31 transplant patients who had proved complete or partial occlusions of the hepatic artery (thrombosis in 29 and marked stenosis in two). Cholangiograms were abnormal in 26 (84%). The most common abnormality, seen in 16 patients, was nonanastomotic contrast leakage from the donor intra- or extrahepatic bile ducts. Strictures of the donor biliary tree occurred in 14 patients, four of whom also had a nonanastomotic bile leak. In 12 of the 14, the strictures were nonanastomotic. Other findings included poor filling of the intrahepatic bile ducts, generalized donor ductal dilatation and irregularity, and intraductal filling defects. Sixteen (89%) of 18 transplants with nonanastomotic contrast leakage had occlusions of the hepatic artery. Of 21 transplants with nonanastomotic strictures, 12 (57%) had occlusions of the hepatic artery. Only two (10%) of 20 transplants with biliary anastomotic strictures had arterial occlusion. We conclude that liver transplant recipients who exhibit nonanastomotic contrast leakage or nonanastomotic strictures on cholangiography should be evaluated for occlusion of the hepatic artery as the probable cause.