Primary hyperaldosteronism is the most common cause of hypertension of endocrine origin. Aldosterone excess is associated with elevated blood pressure, hypokalemia, hyperglycemia and ventricular hypertrophy. The presence of arterial hypertension and low potassium levels in the blood alert the clinician to search for a secondary cause of arterial hypertension. We present the case of a 39 year old with Conn's syndrome (primary aldosteronism by adrenal adenoma), with biochemical and imagiological confrmation and subsequent successful surgery (unilateral adrenalectomy). We present the approach to patients with suspected hyperaldosteronism, interpretation of current tests in our environment and its prognosis.