We report a new case of recurrent, extra-hepatic, deep vein thrombosis occurring after orthotopic liver transplantation for hepatocellular carcinoma complicating 'mixed' alcoholic and post-hepatitic C cirrhosis. Coagulation tests showed activated protein C resistance. The patient's genomic DNA was negative for the factor V Leiden mutation. Analysis of the grafted liver DNA showed that the donor was a heterozygous carrier of the factor V Leiden mutation and that the recipient's activated protein C resistance was acquired through the transplantation. Screening of candidate liver donors for a prothrombotic tendency is controversial. However, this case suggests that patients who develop venous thrombosis after liver transplantation should be screened for thrombophilic abnormalities, bearing in mind that genetic abnormalities which do not affect clotting test results, such as the G20210A mutation in the factor II gene, can only be diagnosed by testing the donor or graft.