Chronic kidney disease (CKD) is associated with an increased risk of cardiovascular disease, and thus is a major worldwide public health problem. Recently, an estimated glomerular filtration rate (eGFR) using the Modification of Diet in Renal Disease equation for Japanese patients was proposed by the Japanese Society of Nephrology. However, the role of eGFR in the assessment of atherosclerosis is not well understood in Japanese patients. We analyzed the relationship between eGFR and severity of arterial stiffness using brachial-ankle pulse wave velocity (baPWV) in 647 adult Japanese patients. baPWV correlated significantly and positively with age, hypertension, diabetes, prior cardiovascular disease, blood pressure, pulse pressure and heart rate, and negatively with eGFR (r=-0.405, p<0.0001). A multiple regression analysis revealed that baPWV correlated independently with eGFR. Furthermore, there was a stepwise increase in baPWV, corresponding to advances in CKD through stages 1 to 5. When CKD stage 3 was divided at eGFR 45 mL/min/1.73 m2, the baPWV of stage 3b (eGFR 30 to 44) was significantly higher than that of stage 3a (eGFR 45 to 59) independent of traditional risk factors, suggesting that an eGFR of 45 mL/min/1.73 m2 may be a critical cut off value to predict arterial stiffness in CKD. In conclusion, the newly proposed eGFR is significantly associated with arterial stiffness, independent of traditional risk factors for cardiovascular disease.