Coronary artery disease (CAD) is a major determinant of long-term prognosis in patients with peripheral artery disease (PAD). We investigated the predictors of CAD in patients with lower extremity PAD.A total of 107 patients with PAD who underwent peripheral and simultaneous coronary angiography were reviewed. PAD was defined as (≥ 50%) stenosis associated with claudication or critical limb ischemia. PAD was divided into proximal and distal lesions. CAD was defined as angiographically significant (≥ 50%) stenosis of coronary arteries.The prevalence of CAD in patients with PAD was 62% (67/107), and of this 62%, only 13% (9/67) had angina and 72% (48/67) had multi-vessel disease. Diabetes significantly increased the risk of CAD in patients with PAD and the odds ratio of having multi-vessel CAD was 2.5 (1.1-5.9, P = 0.037) in multivariate regression analysis. The patients with multi-vessel CAD had more cardiovascular risk factors than those with normal, minimal and single CAD (P = 0.032). Interestingly, the prevalence of proximal PAD was higher in the normal or single CAD group than the multi-vessel CAD group, whereas both proximal and distal involvement of PAD was higher in the multi-vessel CAD group.Diabetes, multi-cardiovascular risk factors, and involvement of both proximal and distal lesions significantly increased the risk of multi-vessel CAD. Therefore, simultaneous CAD evaluation should be considered in patients with lower extremity PAD having diabetes, multi-cardiovascular risk factors, or multi-level disease.