Primary aldosteronism (PA) is the most common cause of endocrine hypertension. PA is a heterogeneous disease, which can be divided into various different subtypes. The mechanisms through which aldosterone exerts an effect on glucose and insulin metabolism are different. Aldosterone suppresses glucose uptake both in vascular smooth and skeletal muscle cells; moreover, aldosterone receptor blockade determines an improvement in insulin sensitivity and in the uptake of glucose by smooth muscle cells. The prevalence of the metabolic syndrome is higher in PA than in essential hypertension (41.1 vs. 29.6%). Further, the prevalence of PA in type 2 diabetes patients with resistant hypertension has been defined to be around 14%. According to published guidelines, resistant hypertension in diabetes needs to undergo screening for PA. Therefore, it clearly results from these different reports how searching for PA in hypertensive patients with diabetes mellitus type 2, or with the metabolic syndrome, could potentially lead to a completely new and integrated approach to both pathologies, based on a targeted therapy, affecting at the same time blood pressure, the metabolic profile and organ damage.