The aim of this study was to evaluate the association between brachial and central blood pressure (bBP and cBP) levels and aortic root dilatation (ARD) in essential hypertensive patients. A total of 190 untreated and treated essential hypertensive patients (mean age, 55 ± 11 years) were considered for this analysis. We measured pulsatile hemodynamics and the proximal aortic diameter directly using tonometry, ultrasound imaging (echocardiography) and Doppler. Ninety-one hypertensive patients had an ARD (defined as aortic size index (ASi)>2 cm/m(2)). Central hemodynamic variables were significantly associated with ASi. Patients with increased ASi were significantly older (60 ± 10 vs. 50 ± 11 years, P < 0.0001) and had higher levels of the augmentation index (AIx; 28 ± 10 vs. 21 ± 10 P < 0.0001), augmentation pressure (AP; 13 ± 6 vs. 8 ± 5 mm Hg, P < 0.0001), and central pulse pressure (cPP; 44 ± 10 vs. 39 ± 8 mm Hg, P<0.0001) compared with patients with normal ASi. In a logistic regression analysis, the AIx was the only significant predictor of ASi. In hypertensive patients, the AIx and cBP were associated with ARD, whereas the bBP was not. Patients with an increased ASi may lose part of the elastic properties of the aorta, demonstrating a strict correlation between ASi and central hemodynamic indexes, in particular, the cPP and AIx.