Twenty-nine limbs (26 patients) that had undergone arterial reconstruction of the femoro-popliteal region from January, 1969 to October, 1978 were studied. The overall early patency rate one month after surgery was 76%. Early occlusion was present in 7 limbs (24%): 2 limbs with endoarterectomies, 2 with Dacron grafts, 2 with vein grafts and 1 with profundaplasty. The early occlusion seemed to be inversely related to the degree of distal run-off. Two-year patency rate for autogenous vein grafts exceeded that of Dacron grafts at each interval of fellow up. Re-operations for late occlusion cases were performed on 7 limbs. Two with vein graft remained patent because of excellent run-off, and another 2 limbs were saved from major amputation. Three limbs with amputation had poor run-off. The results of cases with the repeated surgical procedures were not very satisfactory in cases with poor run-off. With regard to the correlation of the number of distal run-off vessels with graft patency, the average duration of patency was 36 months for limbs with three run-off vessels, 18.5 months with 2 vessels and 6.4 months with one or zero vessel. Autogenous veins seem to be the best bypass graft material at present. The patency rates are directly correlated with the status of the distal run-off vessels in the femoropopliteal bypass.