The aim of this study was to determine if aortic root dimension and blood flow velocity correlate with clinical and echocardiographic characteristics of healthy individuals. To assess the aortic root dimension and blood flow velocity in a healthy population, 503 subjects (253 women and 250 men) aged 18 to 66 years (mean, 36.9 +/- 11.9 years) who were normotensive, free of clinically apparent heart disease and any drug at the baseline examination were included in the study. M-mode echocardiographic measurements were performed according to the criteria recommended by the American Society of Echocardiography. Aortic blood velocity was obtained by pulsed wave Doppler echocardiography. Correlations between aortic root dimension and blood flow velocity and age, gender, body surface area, waist/hip ratio, and echocardiographic parameters such as left ventricular mass, ejection fraction, and left ventricular systolic and diastolic dimensions were evaluated by using regression analysis and Student's t test. Men had greater aortic root dimension (p < 0.001). There were correlations between aortic root dimensions and age, body surface area, waist/hip ratio, and left ventricular mass in both genders (p < 0.05). No correlation was found with left ventricular dimensions and ejection fraction. Aortic blood flow velocity correlated only with age (r = 0.32, p < 0.001). There was no gender difference in aortic blood flow velocity. This study shows that age, gender, body surface area, and waist/hip ratio should be considered in the evaluation of aortic root dimension. However, only age has an important impact on aortic blood flow velocity in both genders.