Fourteen cases are presented of preoperative portal vein thrombosis complicating orthotopic liver transplantation from an experience of 195 transplants carried out between April 1986 and April 1991. In four patients who suffered rethrombosis of the portal vein, the mortality rate was 100 per cent from various causes. Overall there were six deaths; two of those who died had a patent portal vein at death. Three patients underwent retransplantation: one for primary non-function, two for rejection. It is concluded that: (1) portal vein thrombosis should not represent an absolute contraindication to liver transplantation; (2) preoperative screening of prospective transplant recipients for portal thrombosis should be routine; (3) postoperative anticoagulation therapy and periodic Doppler ultrasonographic assessment of portal vein flow are important elements of post-transplant management; and (4) with thrombectomy and portal vein resection an end-to-end portal anastomosis may be performed with good results.