In an attempt to define preoperatively assessed factors that might provide prognostic indications of early graft failure, a series of 350 consecutive femoropopliteal bypass operations have been analyzed with regard to various parameters. Data regarding sex, presence of diabetes and coronary heart disease, severity of symptoms, angiographic assessment of outflow vessels, hemodynamic investigations (ankle systolic pressure index and pulse volume recording), graft material and the site of the distal anastomosis were entered into a computer to study the influence of these factors alone and in combination on early patency rates. Among these factors only the ankle systolic pressure index (ASPI) and pulse volume recording (PVR) significantly affected patency and turned out to be of predictive value in graft prognosis. In particular, when these parameters were severely depressed (ASPI less than 0.40 and PVR less than 2) they became a valuable indicator of early graft thrombosis. By combining different variables we were not able to identify a specific pattern of characteristics for the patient whose graft would probably be doomed to occlusion. Considering the scarcity of accurate prognostic indicators in screening subjects from unsuccessful femoropopliteal reconstruction, we believe that a patient should not be a priori excluded from being considered for surgery if his hemodynamic features (ASPI and PVR) are not greatly reduced.