Arterial stiffness is widely used in assessing arteriosclerosis in the background of increased cardiovascular events. Arteriosclerosis also causes reduction in exercise capacity, which is a most important prognostic factor in patients with cardiovascular disease; however, data on the association between arterial stiffness and exercise capacity are limited. Therefore, a simple and noninvasive measurement of arterial stiffness that reflects the central circulation and exercise capacity is needed. The arterial velocity pulse index (AVI) is a parameter of arterial stiffness measurable with the cuff oscillometric method; however, the clinical utility of this method is unclear. We aimed to evaluate the trend of AVI in patients with coronary artery disease (CAD), and the association between AVI and exercise capacity. A cross-sectional study of 116 patients with cardiac disease (34 CAD and 82 non-CAD patients) was performed. Non-CAD patients were those with any cardiac diseases who did not have proven CAD. The results showed that the AVI was significantly higher in CAD patients than non-CAD patients (P < 0.05, analysis of covariance). The AVI was inversely correlated with peakVO2 (r = −0.239, P < 0.05) and was a significant explanatory variable for peakVO2 in stepwise regression analysis (β = −14.62, t = −2.5, P < 0.05). These results indicate that the AVI is strongly associated with CAD and predictive of the exercise capacity in patients with cardiac diseases. We, therefore, propose that the cuff oscillometric method is clinically useful in evaluating arterial stiffness in patients with cardiac diseases, especially CAD.