Hepatocytes transplantation is viewed as a possible alternative or as a bridge therapy to liver transplantation for patients affected by acute or chronic liver disorders. Very few data regarding complications of hepatocytes transplantation is available from the literature. Herein we report for the first time a case of portal vein thrombosis after intraportal hepatocytes transplantation in a liver transplant recipient. A patient affected by acute graft dysfunction, not eligible for retransplantation, underwent intraportal infusion of 2 billion viable cryopreserved ABO identical human allogenic hepatocytes over a period of 5 h. Hepatocytes were transplanted at a concentration of 14 million/ml for a total infused volume of 280 ml. Doppler portal vein ultrasound and intraportal pressure were monitored during cell infusion. The procedure was complicated, 8 h after termination, by the development of portal vein thrombosis with liver failure and death of the patient. Autopsy showed occlusive thrombosis of the intrahepatic portal vein branches; cells or large aggregates of epithelial elements (polyclonal CEA positive), suggestive for transplanted hepatocytes, were co-localized inside the thrombus.