Left-ventricular hypertrophy (LVH), the primary cardiac manifestation of hypertension, has been identified as the most powerful risk factor for future cardiovascular events causing morbidity and mortality, such as myocardial infarction, congestive heart failure, sudden death, and so forth. The increase in myocardial mass lowers coronary reserve and enhances cardiac oxygen requirements, gives rise to ventricular ectopy, and impairs left-ventricular filling and contractility. Besides hypertension, other risk factors such as obesity, advanced age, valvular heart disease, and other pathologic disorders can cause an increase in the hemodynamic burden and lead to LVH. Nonhemodynamic determinants of left-ventricular mass include dietary salt intake, alcohol, and neurohormones. LVH and its sequelae can be reduced by specific antihypertensive therapy, but despite these promising findings, future epidemiologic studies are necessary to document the clinical benefits of a reduction in LVH.