PURPOSE: To compare the perioperative risks and comorbidities between patients with claudication and patients with critical limb ischemia. METHOD: We retrospectively reviewed the data of 162 patients treated for the leg ischemia at the Vascular Surgery Department at Daegu Catholic University. Excluding patients with acute artery occlusion, vasculitis and Buerger's disease, 127 patients including 58 claudication and 69 critical limb ischemia cases (CI) were studied. To compare perioperative risks, patients data including demographics, physical status classification according to American Society of Anesthesiologists (ASA) and comorbities was collected. RESULT: Mean age was 67.8 years in claudication cases and 68.2 in CI. 98 patients (77.1%) had at least one more associated disease, specifically 87.9% (51/58) in patients with claudication and 66.7% (46/69) in CI. Hypertension was the most frequent disease in both group. Cerebrovascular disease (CVD)(14.5% vs. 12.6%), heart disease (17.3% vs. 10.3%), ASA class 3 (seriously limited physical condition) were more frequent in CI than claudication group (24.6% vs. 15.5%) but not statistically different. 6 patients died during early postoperative period in CI and the claudication group had no deaths. CONCLUSION: Patietns with peripheral arterial diseased patients had high rates of comorbidity (77.1%). More serious disease such as CVD, heart disease were found in CI and associated with higher mortality, which ascertains that more careful attention is be needed, even urgent situations.