Hepatic artery thrombosis (HAT) after liver transplantation is associated with a high incidence of graft failure. The incidence ranges between 2% and 25%, with an overall incidence of approximately 7%. Different risk factors have been associated, but the participation of genetic factors in the cause of HAT is less well studied. A single-base change (G to A) at position 20210 in the 3' untranslated region of the prothrombin gene is associated with increased plasma levels of prothrombin and might therefore increase the risk for thrombosis. We reviewed our HAT experience in 11 years at Medical College of Virginia hospitals of 491 patients undergoing 533 liver transplantations. There were 14 liver grafts with documented HAT (2.62%) in 13 patients. Prothrombin G20210A polymorphism was found in the DNA obtained from 2 of 14 liver allograft tissues (14.2%) but not in the DNA from leukocytes obtained from the peripheral blood of recipients with HAT.