Hepatic artery thrombosis after liver transplantation remains a major problem which may lead to graft loss and retransplantation. Hepatic artery diseases were compared in two matched groups of liver grafted patients. In Group I (67 patients), echodoppler examinations of the graft hepatic artery were carried out after clinical or biological abnormalities became evident. In Group II (85 patients), echodoppler examinations were systematically made during the follow-up at 2 weeks, 1, 3, 6, and 12 months after liver transplantation. In cases of an abnormal echodoppler examination, arteriography was carried out in order to confirm hepatic artery stenosis and to perform endoluminal angioplasty. In Group I, echodoppler examinations revealed no arterial blood flow in three cases and reduction of hepatic blood flow in two cases. Hepatic artery thromboses were always confirmed by angiography, in the latter two cases, a collateral arterial revascularization of the graft was developed. In this group, two retransplantations, one choledocojejunostomy, and four percutaneous radiological biliary drainages were necessary. In Group II, echodoppler results showing a resistive index below 0.5 and a systolic acceleration time above 0.08 s involved 13 arteriographies. Ten stenoses were diagnosed without any biological abnormalities. Nine endoluminal angioplasties were made without any complication. There was no recurrence of stenosis. One pseudoaneurysm of the femoral artery was cured by compression. The early and non-aggressive detection of hepatic artery stenoses after liver transplantation by echodoppler allows treatment by angioplasty in order to prevent hepatic artery thrombosis and reduce retransplantation.