Myasthenia Gravis is a chronic disease of disputed etiology, possibly an auto-immune reaction to the moter end-plate, characterized by exacerbations and remissions, a rare disease entity in Korea. Myasthenia Gravis has offered many anesthetic problems because it affects respiratory muscles occasionally and bronchial secretion from preoperative anticholinesterase therapy. The chief concern is to ensure adequate respiration both during and after operation. During the year 1976-1982, we have experienced the anesthetic management of 8 patients with myasthenia gravis and thymectomy. From our experiences, we conclude that respiratory care and disuse of relaxants is the key to successful management.