Of 94 patients with hypercortisolism, 36 patients with a secreting adenoma underwent unilateral adrenalectomy whereas 58 patients with Cushing's disease underwent bilateral adrenalectomy. Operative death (1%) and post-operative mortality (1 %) occurred in two seriously ill patients with advanced disease who underwent bilateral adrenalectomy. Morbidity was higher in patients with Cushing's disease than in patients with other causes of hypercortisolism, and was related to the length of the illness. Although there were no differences in morbidity, length of operating time, and amount of post-operative intensive care between the anterior abdominal approach and the posterior incision, it is the authors' opinion that the posterior approach is preferable (used in 76 % of the 147 adrenalectomies), with the exception of patients with associated coronary disease for whom this position may not be well tolerated and may hinder the management of any cardiac failure.