Objectives We sought to investigate the plausible interrelationship of exaggerated blood pressure response during exercise (EBPR) with ambulatory arterial stiffness index (AASI) in never-treated patients with uncomplicated essential hypertension. Methods Ninety-nine never-treated hypertensive patients (aged 50.7 years, 61 male) underwent 24 h ambulatory blood pressure (BP) recording, complete echocardiographic study and treadmill exercise testing and were classified as patients with (n = 36) and without EBPR (n = 63) based on the systolic BP elevation at peak exercise (>= 210 mmHg for men and >= 190 mmHg for women). Arterial stiffness was evaluated by means of both AASI and pulse wave velocity (PWV). Results Hypertensives with EBPR, compared with those without EBPR, exhibited significantly higher 24 h systolic BP and pulse pressure (by 3.8 mmHg, P = 0.041 and by 7.2 mmHg, P < 0.001, respectively), and decreased peak early diastolic velocity and peak early diastolic velocity/peak atrial systolic velocity ratio (by 1.1 cm/s and by 0.11, both P < 0.05, respectively). PWV and AASI values were higher in the EBPR group compared with the normal response group independently of confounders (by 0.9 m/s, P < 0.001 and by 0.06, P = 0.043, respectively). PWV (beta = 0.308, P = 0.008) and 24-h pulse pressure (beta = 0.297, P = 0.010), but not AASI, were independently associated with peak exercise systolic BP. Conclusion EBPR constitutes a sign of premature cardiovascular stiffening in the setting of uncomplicated hypertension. The close relationship between EBPR and PWV but not AASI enhances the concept of PWV as a superior measure of arterial stiffness and constitutes an important factor in the interpretation of EBPR-linked cardiovascular risk. Blood Press Monit 15: 132-138 (C) 2010 Wolters Kluwer Health vertical bar Lippincott Williams & Wilkins.