Patients with resistant hypertension have a higher incidence of secondary causes of hypertension compared with the general hypertensive population. It is important to screen such patients for secondary causes of hypertension because appropriate treatment can lead to improved blood pressure control or even cure these patients, and thus avoid the cardiovascular morbidity and mortality associated with uncontrolled hypertension. One common cause of secondary hypertension, often associated with hypokalemia, is primary hyperaldosteronism or Conn syndrome. Aldosterone is a mineralocorticoid hormone produced in the outer layer of the adrenal cortex (the zona glomerulosa); its primary action is to increase sodium and water reabsorption by the kidney. Once the diagnosis of primary aldosteronism is made, it is necessary to determine if aldosterone production is unilateral or bilateral. When production is unilateral (most often from a functional adenoma), surgery is potentially curative. The authors report a case and review the diagnostic workup of Conn syndrome in which resistant hypertension and hypokalemia were cured by unilateral adrenalectomy.