Myasthenia gravis is an autoimmundisease characterized by muscle fatigability due to a reduction in available acetylcholinereceptors at neuromuscular junction. Although the role of the thymus in the pathophysiology remains obscure, the results of thymectomy are out of discussion. However, controversy continues concerning the indications for thymectomy. In a period of six years and a half, 24 patients underwent a thymectomy. 22 of the patients benefited from the procedure. Their was no relation with sex, age, and severity of the disease; but how sooner we operate, how greater the changes for a total remission. With this results we propose thymectomy as essential in the treatment of myasthenia gravis. We found no relationship between anatomopathological results and these of the thymectomy. But we can confirm that a reduction in the acetylcholine antibodies titer is not essential for clinical benefit.