The present review updates myasthenia gravis. Immunopathogenesis of this condition, the clinical picture and degrees of involvement according to Osserman's classification, diagnostic procedures currently available, medical treatment and repercussion on the patient who is going yo be thymectomized are discussed. We review the works of several authors as far as concern to the use of muscle relaxants in myasthenic patients, peroperative monitoring of neuromuscular blockade, anesthetic techniques to be used, analgesia and intensive care required during postoperative period.