The effect of unilateral adrenalectomy in primary aldosteronism was analyzed in 38 patients with unilateral adenoma, 12 cases with idiopathic bilateral hyperplasia and 1 patient suffering from an aldosterone-producing carcinoma. Responses to surgery differed markedly. In all 38 adenoma cases plasma aldosterone dropped to normal levels and remained within normal range during a mean follow-up period of 75 ± 12 months. 23 (61 %) of these patients became normotensive without medication and thus could be classified as definitely cured. 34% (13 patients) improved (normotensive under medical treatment) and only 2 cases (5 %) remained hypertensive despite sufficient medical treatment. In the hyperplasia group, however, the effect of adrenalectomy was disappointing. None of these subjects showed a long-lasting normalization of aldosterone secretion. A temporary remission for no more than 3–4 months was achieved in only 3 patients. In a fourth case with macronodular hyperplasia, primary aldosteronism relapsed after a 6-year period of normal blood pressure and aldosterone values. Therefore, 6 years after adrenalectomy no hyperplasia patient was definitely cured in contrast to 61 % of the adenoma cases. The problems in the management of hypertension in adrenal hyperplasia are furthermore documented by a poorer blood pressure control despite antihypertensive medication and a high rate of vascular complications. During the follow-up, 3 of 12 hyperplasia patients experienced a cerebrovascular event and 1 a myocardial infarction.