The aim of this study was to identify the influence of diabetes mellitus on patients with atherosclerosis obliterans (ASO) of the lower extremities. A prospective study was designed to compare differences between ASO patients with and without diabetes mellitus in regard to clinical characteristics and outcomes of management. Two hundred fifty-three consecutive (61.1%) diabetic and 161 (38.9%) nondiabetic patients were included in this study. Crural artery occlusion occurred more frequently in diabetic patients (tibioperoneal segment 26.5% vs 14.3%; p = .003). Diabetic patients had higher comorbidities, such as ischemic heart disease, disabling stroke, and renal failure. Infection requiring urgent surgical intervention was higher in diabetic patients (39.1% vs 24.2%; p = .001). This required primary major amputation in limb-threatening ischemia superimposed with infection (27.6% vs 17.7%; p = .037). The feasibility (67.2% vs 69.8%; p = .651) and success (74.4% vs 79.0%; p = .481) of revascularization between the two groups were comparable. Diabetic patients often needed more distal revascularization for limb salvage (34.4% vs 18.5%; p = .019). The mortality rate after revascularization was higher in diabetic patients (13.3% vs 2.5%; p = .009). Diabetes mellitus per se has no direct impact on limb salvageability in limb-threatening ischemia. The parity of feasibility and success in revascularization between the two groups should encourage attempts at limb salvage revascularization in diabetic patients.