Mineralocorticoid hypertension is hypertension associated with the presence of hypokalemia, metabolic alkalosis, and suppression of plasma renin. Mineralocorticoid hypertension represents only 10% of patients with essential hypertension. However, its recognition is important because it is a potentially reversible cause of hypertension. Primary hyperaldosteronism is the most common form of mineralocorticoid hypertension. It is current clinical practice to use the plasma aldosterone-renin ratio and the absolute plasma aldosterone level as screening tests. Confirmatory suppression tests and adrenal imaging are performed in appropriate patients. Three monogenic forms of mineralocorticoid hypertension have been identified including Liddle's syndrome, glucocorticoid-remediable hypertension, and apparent mineralocorticoid excess. In a number of patients with mineralocorticoid hypertension, hypokalemia can be a variable finding. This review highlights mineralocorticoid biology and important features of primary hyperaldosteronism and monogenic hypertension.