Aim To investigate the relationship between leptin and lower extremity atherosclerosis in patients with type 2 diabetes mellitus(T2DM). Methods Totally 71 male patients with T2DM were divided into 38 patients with lower extremity atherosclerosis and 33 patients without lower extremity atherosclerosis according to the results of lower limb artery color ultrasound. General information, biochemical indicators and serum leptin levels of the two groups were compared. Multivariate Logistic regression was used to analyze the risk factors of lower extremity atherosclerosis in T2DM. Results Serum fasting blood glucose (7.97(6.7,9.37) mmol/L vs 6.97(6.7,8.04) mmol/L), glycated haemoglobin A1c (HbA1c)((8.15%±1.79%) vs (7.31%±1.22%)) and leptin levels ((227.60±58.08) ng/L vs (176.60±43.94) ng/L) were significantly higher in the group with lower extremity atherosclerosis than those in the group without lower extremity atherosclerosis (P＜0.05). High serum leptin level(OR=1.6,5%CI 1.002～1.030, P＝0.024) and HbA1c(OR=1.5,5%CI 1.060～2.874, P＝0.029) were the risk factors of lower extremity atherosclerosis in patients with T2DM. Conclusion The serum level of leptin is the risk factor of lower extremity atherosclerosis in patients with T2DM.