Left ventricular hypertrophy (LVH) is both a target organ response to hypertensive vascular disease and a factor that might be responsible for other cardiovascular events. Therefore we studied by means of echocardiography 41 patients with untreated hypertension classified into 4 groups according to electrocardiographic and chest X-ray LVH criteria. The patients in group IV had in addition a history of coronary disease. Thirty-seven patients (92%) presented concentric LVH and 4 patients combined LVH and dilatation. Five patients from group IV presented impairment of interventricular septum or posterior wall motion. Thirty-seven patients (92%) had increased left ventricular mass (p less than 0.01). Ejection fraction was normal in groups I, II and III but significantly decreased (p less than 0.001) in group IV. We conclude that LVH is part of the natural evolution of hypertensive vascular disease. Echocardiography proved to be the most indicated method for the assessment of cardiac dimensions and function in hypertensive heart disease.