Myasthenia gravis is a disease characterized by muscle weakness upon exertion of an involved muscle group and partial return of function eithe with rest or the administration of anticholinesterase. It is generally thought that myasthenia gravis is caused by an autoimmune response associated with the thymus gland and thymectomy is considered to be the treatment of choice for countering this autoimmune process. It is a well known fact that perioerative nticholinesterase therapy, muscle relaxant administration during operation and postoperative respiratory management are in dispute. We described a case of a 42 year old male myasthenic patient with mild symptoms who needed 4 days of artificial ventilatory support following thymectomy.