Liver transplantation is a technically complex and long surgical procedure. A large quantity of various materials such as catheters, sutures, needles and clips are frequently used during the procedure. These materials may enter in the liver from the vascular or biliary orifices inadvertently. A 50-year-old patient who had hepatic failure due to HBV underwent a deceased-donor liver transplantation. The deceased donor was a 75-year-old HbsAg(+) man. The recipient had subfebrile fever and leukocytosis post-operatively. A control computed tomography revealed a cuneiform ischemic area, and a foreign body inside the right anterior portal vein branch proximal to this ischemic region. A 10-F Nelaton catheter, 5-cm long, was removed from the portal vein by surgery. Retrospectively, we understood that the portal vein was cut during the back-table procedure and the portal vein catheter was replaced with a larger one for better irrigation. Most probably, the original catheter was cut together with the portal vein, and the tip of the catheter was retained in the portal system and migrated into the liver. As far as we know, such a complication of liver transplantation has never been described previously.