Recently, robotic technology in the surgical area has gained wide popularity. However, in the filed of head and neck surgery, the applications of robotic instruments are problematic owing to spatial and technical limitations. The authors performed robot-assisted endoscopic thyroid operations in consecutive thyroid tumor patients using the newly introduced da Vinci S surgical system. Herein the authors describe the technique used and its utility for the operative management of thyroid tumors. From October 2007 to November 2008, 338 patients underwent robot-assisted endoscopic thyroid operations using a gasless, transaxillary approach. All procedures were successfully completed without conversion to an open procedure. Patient's clinicopathologic characteristics, operation types, operation times, the learning curve, and postoperative hospital stays and complications were evaluated. The mean patient age was 40 years (range, 16-69) and the male to female ratio was 1:16.8. Two hundred and thirty-four patients underwent less than total and 104 underwent bilateral total thyroidectomy. Ipsilateral central compartment node dissection was conducted in all malignant cases. Mean operation time was 144.0 minutes (range, 69-347) and mean postoperative hospital stay was 3.3 days (range, 2-7). No serious postoperative complication occurred; there were 3 cases of recurrent laryngeal nerve injury and 1 of Horner's syndrome. Our technique of robotic thyroid surgery using a gasless, transaxillary approach is feasible and safe in selected patients with a benign or malignant thyroid tumor.