Primary aldosteronism is the most common cause of secondary hypertension, incurring significant cardiovascular morbidity and mortality. Our understanding of this disease has evolved substantially during the past decade. Recently, the molecular basis of primary aldosteronism has begun to be unraveled, with the discovery of mutations in potassium channel (KCNJ5), ATPases (ATP1A1, ATP2B3), and calcium channel (CACNA1D), and aberrant Wnt/β-catenin signaling. The most recent data suggest that 95% of cases are sporadic, whereas 5% of cases are hereditary. Pathologic correlates of primary aldosteronism include adrenal cortical hyperplasia, adenoma, and carcinoma. Although the most common clinical presentation is bilateral adrenal cortical hyperplasia, this entity is usually treated medically. Therefore, in the setting of primary aldosteronism, surgical pathologists are most commonly exposed to adrenocortical adenomas and the odd occasional carcinoma. This review provides an update on the current knowledge of primary aldosteronism and discusses the clinicopathologic correlations of this important disease.