A 13-year-old boy was diagnosed as suffering from pituitary-dependent Cushing's syndrome. He was treated with 2.0 g of metyrapone daily as the sole treatment for four years. All clinical and biochemical stigmata of Cushing's disease disappeared within a few months. The patient grew 23.0 cm in four years and regained normal health. No significant side effects of metyrapone were noticed. Administering the medication at 2 PM and 8 PM allowed higher cortisol levels in the morning and noon hours than in the evening and night, approximating the normal diurnal variation in cortisol production. We conclude that metyrapone may be considered the sole treatment in patients with Cushing's disease.