Background: The association between abnormal rise in systolic blood pressure (BP) during exercise and cardiovascular morbidity has been suggested. Although augmented rise of angiotensin II during exercise has been suggested as a neurohumoral mechanism, contribution of mechanical property of arterial tree to the development of exaggerated BP response to exercise has not been clearly elucidated. We hypothesized that aortic stiffness, assessed by aortic pulse wave velocity (PWV), would be associated with exaggerated BP response to exercise. Methods: One-hundred seventy-seven subjects (68 men, 59 짹 12 years) who were referred to exercise echocardiography were enrolled. The subjects who had resting BP ��� 140/90 mmHg were excluded. Brachial BP was measured at rest and during supine bicycle exercise (25 Watts, 3-minute increments). Central aortic stiffness was estimated by measuring PWV at rest. The subjects were divided into tertiles by their PWV: Low PWV (6.1 짹 0.6 m/sec, n=58), medium PWV (7.6 짹 0.4, n=60) and high PWV (10.0 짹 2.0, n=59). Results: Subjects of high PWV group were older but there was no difference in gender distribution. At rest, mean systolic BP was 122 짹 11 mmHg and there was no significant difference in systolic BP between three groups (p=0.448). However, during 50 Watts of exercise, systolic BP was significantly higher in subjects with high PWV compared with low and medium tertiles (p=0.007). The magnitude of increase in systolic BP from rest to exercise was also significantly higher in subjects with high PWV (p=0.021) (Figure). In simple correlation analysis, the change in systolic BP from rest to 50 Watt was significantly correlated with PWV (r = 0.254, p=0.004). Conclusion: An exaggerated BP response to exercise who have normal resting BP was associated with increased aortic stiffness. Therefore, aortic stiffness assessed with PWV would be one of the important determinants of BP response to exercise.