Objective: To compare the efficacy of gasless robotic surgery through transaxillary approach and open surgery for papillary thyroid carcinoma (PTC). Methods: The data of patient undergoing robotic surgery through transaxillary approach and traditional open surgery for PTC at the Sun Yat-sen Memorial Hospital, Sun Yat-sen University, from November 2016 to June 2023 were retrospectively analyzed. A 1∶1 propensity score matching (PSM) was performed to balance age, sex, extent of surgery, tumor size, capsule invasion, and multifocality. Surgical data, postoperative pathological data, complications, postoperative 2-month visual analog scale (VAS) scores for aesthetics, and follow-up data were compared between the two groups. Results: A total of 728 PTC patients were included. There were 339 patients in the robotic group, among which 262 were female (77.3%) and 77 were male (22.7%), with the age of [M (Q1, Q3)] 39 (32, 46) years and a body mass index (BMI) of 22.8 (20.7, 25.0) kg/m². Meanwhile, 389 patients were in the open group, among which 290 were female (74.6%) and 99 were male (25.4%), with the age of 47 (38, 55) years and a BMI of 23.2 (21.3, 25.5) kg/m2. Further analysis after PSM (there were 264 cases in both groups) showed that in the subtotal thyroidectomy and central neck dissection (LT+CCND) subgroup, the robotic group had longer operative time, higher blood loss, and greater drainage volume compared with the open group [100 (80, 130) min vs 60 (50, 80) min; 10 (10, 20) ml vs 10 (10, 20) ml; 103 (69, 145) ml vs 75 (57, 98) ml; all P<0.001], and the central lymph node metastasis rate was higher in the robotic group [45.6% (57/125) vs 31.8% (47/148), P=0.019]. In the total thyroidectomy and central neck dissection (TT+CCND) subgroup, the robotic group also had longer operative time, higher blood loss, and greater drainage volume compared with the open group [150 (110, 180) min vs 85 (75, 100) min; 20 (10, 20) ml vs 10 (10, 20) ml; 155 (107, 206) ml vs 90 (70, 120) ml; all P<0.001]. The incidence of chest skin numbness at 3 months postoperatively was higher in the robotic group compared with the open group (12.9% vs 0, P<0.001), while there were no statistically significant differences in other postoperative complications (all P>0.05). The VAS score at 2 months postoperatively was higher in the robotic group compared with the open group [9 (9, 9) vs 8 (7, 9), P<0.001]. Three cases of contralateral lobe recurrence occurred in the open group, while there were no case of recurrence in the robotic group. The 5-year overall survival rate was 100.0% in both the robotic and open groups, and there was no statistically significant difference in the 5-year disease-free survival rate between the robotic and open groups (100.0% vs 98.6%, P=0.068). Conclusion: Gasless robotic surgery through transaxillary approach for total thyroidectomy or lobectomy in the treatment of PTC is safe, feasible, and effective, with good cosmetic outcomes and comparable efficacy to traditional surgery.