Aldosterone blockade is now seen as a crucial therapeutic strategy in the management of cardiovascular disease progression. There is increasing evidence that blocking the rennin-angiotensin-aldosterone system results in a reduction in overall cardiovascular risk. For 40 years, the only agent in this class was spironolactone. Despite its efficacy, the sexual side effects of spironolactone have resulted in poor compliance at best and discontinuation of therapy at worst. A newer agent, eplerenone, has been recently licensed for the treatment of heart failure and in the US also for hypertension. This article reviews the pathophysiology of aldosterone and critically reviews the present evidence for the efficacy and potential role for the new selective aldosterone-receptor antagonist, eplerenone.