The interest in the therapeutic potential of aldosterone antagonists in essential hypertension comes from the recently discovered nonclassical pathways of aldosterone actions, above all the presence of extra-adrenal aldosterone production and the discovery of aldosterone proinflammatory and profibrotic actions. The review begins with the discussion of experimental studies on animals, demonstrating the role of aldosterone in cardiovascular remodeling and the effects of aldosterone blockade on hypertensive target organ damage. Then recent clinical studies are presented, that confirm in humans the deleterious role of aldosterone, in particular in the development of myocardial hypertrophy, cardiovascular fibrosis and arterial stiffness. Finally the results of clinical studies on essential hypertensive patients are discussed, evaluating the efficacy of aldosterone antagonists in lowering blood pressure, but, more important, in protecting against target organ damage.