The indications for supra-articular prosthetic bypass is still a controversial subject in cases where the internal saphenous vein can be used, or in stage II cases. These bypasses cannot be performed unless they are as permeable as venous bypasses and do not greatly increase the risk of exaggerating the symptomatology in case of thrombosis. In order to evaluate the outcome of these bypasses, we evaluated retrospectively our series of 81 surpa-articular femoro-popliteal prosthetic bypasses performed between 1987 and 1989. The man age of the patients was 64 years and 38% of them had coronary artery disease. Forty-six bypasses (57%) were performed in advanced stage II patients, 20 in stage III patients (25%) and 15 in stage IV (18%). Mean follow-up is 42 months. At 36 months, primary overall permeability was 65%. This level of permeability is in agreement with the data in the literature and is independent of the initial clinical stage, the downstream arterial network and the size of the prosthesis. The outcomes observed in our series would favour use of P.T.F.E. in the first intention operation to save the vein for possible subsequent use at stages III and IV. Inversely, for stage II, prospective randomized studies should be conducted in order to compare endovascular techniques and medical treatments.