Left ventricular hypertrophy (LVH) of hypertension is characterized by an increased ventricular mass due to myocardial cell hypertrophy and development of collagen and capillaries. Detected in man by electrocardiography and echocardiography, it is difficult to study due to the lack of sensitivity of EEG and the poor reproductibility of echocardiography, and by the lack of systematization of the analysis criteria adopted by investigators. Despite these uncertainties, the pejorative prognostic value of LVH has been clearly established and, based on its relationship with other risk factors, it can be considered to be an integrator of cardiovascular risk, justifying the use of this marker rather than other more variable indicators such as BP. The improved prognosis related to regression of LVH in response to treatment is currently controversial. Preliminary results indicate a reduction of morbidity-mortality in hypertensive patients when LVH is decreased; these findings must be confirmed before reduction of LVH can constitute an objective and antihypertensive treatment.