ObjectiveTo compare clinical effects of enlarged thymectomy for the treatment of myasthenia gravis (MG) complicated with thymoma via subxiphoid and subcostal arch thoracoscopic resection versus median sternotomy resection. MethodsWe retrospectively analyzed the clinical data of patients with MG complicated with thymoma admitted in Tangdu Hospital of the Air Force Military Medical University between December 2011 and December 2021. Patients who underwent subxiphoid and subcostal arch thoracoscopic enlarged thymectomy were allocated to a SR group, and patients who underwent median sternotomy enlarged thymectomy were allocated to a MR group. Perioperative outcomes were compared between the two groups. ResultsA total of 456 patients were collected. There were 51 patients in the MR group, including 30 males and 21 females aged 23-66 (49.5±11.8) years. There were 405 patients in the SR group, among whom 51 patients were matched to the MR group by propensity score matching, including 28 males and 23 females aged 26-70 (47.2±12.2) years. The operations were accomplished successfully in all patients, and no conversion to thoracotomy occurred in the SR group. The SR group had advantages in the operation time, intraoperative blood loss, chest drainage duration, hospital stay time, patients’ satisfaction level, pain score and complications (all P<0.05). No statistical difference was found in the number of intraoperative lymph node dissection stations, number of intraoperative lymph nodes dissected or remission of MG between the two groups (P>0.05). ConclusionSubxiphoid and subcostal arch thoracoscopic enlarged thymectomy and lymphadenectomy is a safe, effective and feasible minimally invasive procedure for the treatment of MG complicated with thymoma.