ABSTRACT: This aim of this study was to compare three approaches of extended thymectomy for the treatment of early-stage thymomas, which included robot-assisted thoracic surgery (RATS), video-assisted thoracic surgery (VATS), and median sternotomy (MS) perioperative parameters.A retrospective study was conducted on 123 patients with early stage thymomas at Shanghai Chest Hospital who underwent extended thymectomy between February 2009 and August 2014. Among them, MS was performed on 37 patients, VATS was performed on 35 patients, and RATS was performed on 51 patients. A series of outcome measures were compared between these three approaches, including operative time, intra-operative blood loss volume, occurrence of intra-operative complications, post-operative pleural drainage duration, post-operative pleural drainage volume, duration of hospital stay, and the incidence of post-operative complications.A series of intra- and post-operative parameters showed significant differences in intra-operative blood loss volume, mean post-operative pleural drainage duration, pleural drainage volume and mean duration of hospital stay. For these parameters, during further analysis, significant differences were also demonstrated for comparisons between any two groups. RATS reduces the post-operative drainage duration and volume (2.88 vs. 3.77 and 4.41 days, P<0.05; 352.2 vs. 613.9 and 980 mL, P<0.05) and the hospital stay versus the MS and VATS groups (4.3 vs. 5.5 and 6.6 days). Three patients experienced post-operative complications in the MS group, and no post-operative complications occurred in the RATS or VATS group.RATS and VATS both appear feasible and safe for the resection of early-stage thymomas as compared to MS. RATS is less invasive than VATS with a shorter post-operative pleural drainage duration time, a reduced drainage volume, and a shorter hospital stay.