Patients in critical care unit (CCU) are the most at risk of developing AKI. In most cases a mechanism of ischemia/reperfusion has a central role in the development of AKI. Aldosterone has traditionally been recognized as a mediator that maintains water and sodium homeostasis. Nevertheless, there are enough evidence in humans and experimental models that aldosterone might mediate detrimental effects on renal function and structure in pathophysiological conditions. Indeed, several experimental studies from our laboratory have shown that mineralocorticoid receptor blockade protects the kidney against ischemia/reperfusion injury.