Cushing's disease is almost always due to ACTH hypersecretion by a pituitary adenoma. Surgical excision is the only curative treatment. MRI together with ACTH assay in the inferior petrous sinus provides the diagnosis and localization in 80% of cases. Surgery should be wide in all cases, going beyond the limits of the adenoma visible on the MRI. Total or subtotal antihypophysectomy may be indicated if the imaging is negative and no lateralization can be determined from ACTH assays. In case of therapeutic failure, reoperation must be proposed early. A 5-year follow-up is required before the definitive results of surgery can be assessed. Cure is evaluated on the basis of postoperative cortisol levels (<3 - 5 g/dl). Initially, the rate of remission varies from 70 to 85%. Success after a second operation is to the order of 80 to 90%. The surgical risk for ACTH adenomas is higher than for other secreting adenomas (CSF fistulae, meningitis, thromboembolism, visual disorders), certainly due, in part to subtotal or total antihypophysectomy.