Aim: The cardio-ankle vascular index (CAVI) reflects arterial stiffness from the aorta to the ankle, independent of blood pressure (BP). We investigated the age-stratified CAVI in healthy, normotensive individuals to evaluate the effects of age on arterial stiffness.Methods: The CAVI and peripheral BP were determined in healthy, normotensive Koreans 20 to 79 years of age. The subjects had no history of cardiovascular disease and did not take any medications for hypertension, diabetes mellitus or dyslipidemia (N=1,380; 44.1% in men).Results: The mean systolic blood pressure (SBP), diastolic blood pressure (DBP) and pulse pressure (PP) were 117, 75 and 42 mmHg, respectively. The CAVI increased linearly with age and was determined using the following equation: CAVI= 5.0+0.048×age (year) in men (r2 = 0.395, p<0.001), CAVI= 4.8+0.045×age (year) in women (r2 = 0.450, p<0.001). However, SBP, DBP and PP did not change progressively with age. Age emerged as the major determinant of the CAVI in a stepwise multiple regression analysis (r2 change= 43.1%).Conclusions: The CAVI scores increased with age in the healthy, normotensive individuals, whereas SBP, DBP and PP did not. Age was the dominant risk factor for the progression of arterial stiffness. These data suggest that the CAVI is a sensitive marker of the arterial aging process, above and beyond conventional upper arm BP.