To determine whether hypertension and overweight status are associated with increased carotid intimal-medial thickness (cIMT) in children, vascular ultrasonography was performed in newly diagnosed hypertensive patients ( n=53) and normotensive controls ( n=33). Hypertensive subjects were identified either by referral or by systematic school-based hypertension screening. Hypertension was defined as blood pressure above the 95th percentile based on current Task Force criteria, and overweight was defined as body mass index (BMI) >25 kg/m(2). cIMT was assessed by high-resolution vascular ultrasonography of the distal common carotid artery. Hypertensive subjects had a higher cIMT than normotensive subjects (0.62 vs. 0.53 mm, P<0.00001). This difference remained significant after controlling for the effects of gender, race, age, height, weight, and BMI. Similarly, overweight subjects had a higher cIMT than normal-weight subjects (0.63 vs. 0.54 mm, P<0.0001). Subjects with both systolic and diastolic hypertension had higher cIMT than those with isolated systolic hypertension (0.67 vs. 0.60, P<0.05). cIMT showed significant positive pairwise correlation with age, height, weight, BMI, and systolic blood pressure. Among all clinical variables analyzed, cIMT was most strongly correlated with BMI ( r=0.53, P<0.001). These results provide further evidence that vasculopathy occurs in association with known cardiovascular risk factors such as hypertension and obesity during childhood.