Polytetrafluoroethylene grafts were used for 175 femoropopliteal reconstructions with a cumulative 3 year life table patency rate of 77%. Reoperation for early or late failure was required in 27 patients to achieve this patency rate. If these 27 failures were calculated as nonpatent grafts, 3 year patency would be 62%. Thirty month life table patency rates were 94 and 91% for polytetrafluoroethylene axillofemoral and femorofemoral bypasses, respectively. Twenty-two polytetrafluoroethylene axillopopliteal bypasses were performed because of infection in the groin, previously failed reconstructions or unavailability of femoral vessels due to disease. The 2 year life table patency rate was 69%, with nine of the grafts patent for more than 1 year. Forty polytetrafluoroethylene bypasses to arteries at the ankle or in the foot resulted in a 2 year life table patency rate of 48%. Thus, polytetrafluoroethylene grafts show early promise as a vascular prosthesis. Although further study will be required to define the exact role of this new arterial substitute, it already can facilitate the performance of otherwise difficult or impossible limb salvage procedures.