Two-dimensional echocardiography was performed in 29 normotensive obese subjects and 21 hypertensive obese subjects representative of the Chilean population. The left ventricular mass (LVM) did not correlate with height or body surface area (BSA) in these patients, but positively correlated with body mass index (BMI), tricipital skinfold thickness and blood pressure (BP). The LVM/BSA ratio was significantly higher in the hypertensive subjects and was correlated with BP only. Left ventricular hypertrophy (LVM/BSA > 120 or 150 g/m2 in women or men, respectively) was found in 28% of normotensive and 58% of hypertensive subjects (P = 0.036). No statistical differences were found in relative wall thickness (RWT) between both groups. Posterior wall thickness was independently associated with BP while interventricular septum thickness was positively associated with the waist/hip ratio. Systolic function, evaluated through fractional shortening and end systolic diameters, was negatively and independently associated with body fat area. Left ventricular hypertrophy is a prevalent condition in these obese subjects. Hypertension seems to exert an additive effect, mainly increasing posterior wall thickness. Fat accumulation was negatively related to systolic function in this sample, irrespective of blood pressure.