The hepatic artery is important in preventing biliary ischemia and obstruction after bile duct reconstruction or orthotopic liver transplantation in the rat. A technique of orthotopic liver transplantation in the rat with reestablishment of the arterial inflow is described, suitable for studies in immunology and preservation. Reestablishment of both venous and arterial inflow is required to minimize biliary complications. General survival, hepatic cellular function, and biliary drainage are all improved by rearterialization. In all these features, the rat illustrates characteristics applicable to human liver transplantation. The vital requirement of the adequacy of blood supply to the bile duct in liver transplantation surgery in all species is highlighted by these findings, which indicate clearly the importance of an arterial blood supply in rat liver transplantation and bile duct surgery.