The results of 305 femorotibial bypass grafts performed in 246 patients are presented. Of these operations 246 were primary and 58 secondary or tertiary. A total of 66 diabetic patients were in the series. An autogenous saphenous vein graft was employed in 196 primary operations, the other grafts used being PTFE, human umbilical cord vein graft, venous allograft and knitted dacron velour graft. Hospital mortality was 8 patients (2.6%), while late mortality was 73 patients, 39 of them having had patent grafts. There were 89 (29.2%) immediate or early hospital failures. Two-hundred-sixteen grafts were followed for a mean observation time of 62.3 +/- 5.7 months. The cumulative patencies were analyzed using the life-table method. One, five, and ten year overall patencies for saphenous vein grafts as indicated by claudication were 73%, 53% and 35%, respectively. In rest pain, the patency rates were 62%, 46% and 40% at similar intervals. In impending gangrene the patencies were 43%, 35% and 20%, respectively. The patencies for arterial substitutes were generally poor, i.e., 35% and 15% at one and five years. None of the graft substitutes were followed for up to ten years. Diabetic patients had a significantly lower patency rate than nondiabetics (p = 0.002). The impact was remarkable if impending gangrene co-existed. In all these situations the early graft failure ensued. Both the run-off and inflow status affected the patency rates. This was significantly lower (p = 0.001) when only one distal branch was visualized in angiography.