PURPOSE: The aim of this study is to analyze the patency rates according to the risk factors and comorbidities in patients treated with endovascular treatments or arterial bypass surgery due to chronic arterial occlusive disease in the lower extremity. METHODS: Two hundred fifty-seven patients were treated for chronic arterial occlusive disease in lower extremity from January 2000 to December 2010 at Chonbuk National University Hospital; of the 257 patients, we retrospectively reviewed medical records of 142 patients who could be followed-up. We analyzed the patency rates according to the Trans-Atlantic Inter-Society Consensus (TASC) II classification, risk factors and comorbidities. RESULTS: One year, three year, and five year patency rates according to TASC classification had no statistical significance (P=0.301), and those risk factors and comorbidities associated with each other also had no statistical significance. However, the patency rates according to the number of risk factors and comorbidities demonstrated statistical significance (P=0.004), respectively. In addition, when sum of the total number was above 6, the patency rates were the poorest with statistical significance (P<0.001). Also, these analyses had statistical significance in the groups regarding TASC C, D (P<0.001), aorto-iliac lesions (P<0.001) and femoro-popliteal lesions (P<0.001). CONCLUSION: Analysis of risk factors and comorbidities in patients with chronic arterial occlusive disease in the lower extremity can be useful in predicting the patency rates prior to endovascular treatments or arterial bypass surgeries.