Objective To evaluate the effect of perioperative immune-directed remission therapy in prevention of myasthenic crisis after thymectomy for general myasthenia gravis patients.Methods 58 patients with general myasthenia gravis who underwent thymectomy from January 2003 to December 2006 were reviewed.The remission induction therapy was conducted in all the patients preoperatively with immunoglobulin or in conjunction with high-dose glucocorticoid,and the remission was maintained by short term continuing infusion of immunoglobulin or slow tapering of corticosteroid postoperatively.Post operative myasthenic crisis and other respiratory complications were analyzed and the effectiveness of the operation was estimated by the remission rates at follow-up of 1 month to 3 years.Results There was no operative death,nor early post-operative myasthenic crisis or cholinergic crisis.No retintubation or tracheotomy was performed postoperatively.Complications related to extended thymectomy occurred in 3 patients (two cases of unilateral diaphragmatic paralysis and one Left recurrent laryngeal nerve paralysis).The total effective rates were 91.4%. Complete remission and partial remission were gained in 16 patients (27.6%) and 37 patients (63.8%) respectively.Conclusion Short-term perioperative immune-directed remission therapy could effectively prevented post-operative myasthenic crisis and respiratory complications in addition to standardized operative maneuver and optimized early postoperative management.