Background <p>Endoscopic technology continues to evolve, expanding the clinical application spectrum of various endoscopic thyroidectomy approaches. However, comparative studies between gasless trans-subclavian approach endoscopic thyroidectomy (GTSA-ET) and gasless trans-axillary approach endoscopic thyroidectomy (GTAA-ET) remain notably scarce in the current literature. In this study, we aimed to compare the clinical efficacy of GTSA-ET and GTAA-ET in the treatment of papillary thyroid carcinoma (PTC).</p> Methods <p>This study was conducted on 160 patients with cN0-stage PTC who were enrolled between December 2023 and July 2024. The patients were randomly assigned to either the GTSA-ET group (<i>n</i> = 80) or the GTAA-ET group (<i>n</i> = 80) at a 1:1 ratio. Perioperative outcomes, postoperative complications, postoperative neck function, surgical site pain and numbness scores, and incision satisfaction were systematically observed and compared between the two groups.</p> Results <p>Compared with the GTAA-ET group, the GTSA-ET group exhibited a significantly shorter operative time (<i>p</i> &lt; 0.001), a higher rate of complete central compartment (level VI/VII where applicable) exposure (<i>p</i> = 0.028), and a greater total number of dissected central lymph nodes (<i>p</i> &lt; 0.001). At 1 month postoperatively, patients in the GTSA-ET group reported significantly less neck movement traction sensation than those in the GTAA-ET group (<i>p</i> &lt; 0.05). No statistically significant difference was observed in swallowing traction sensation between the two groups (<i>p</i> &gt; 0.05). Additionally, patients in the GTSA-ET group experienced significantly milder pain and numbness in the anterolateral chest region compared with the GTAA-ET group (<i>p</i> &lt; 0.05). There was no significant difference in incision satisfaction scores between the two groups (<i>p</i> &gt; 0.05).</p> Conclusions <p>GTSA-ET offers distinct advantages over GTAA-ET, including a shorter operative time, a higher rate of complete central compartment (level VI/VII where applicable) exposure (supporting more thorough central compartment lymph node dissection), a greater number of dissected central lymph nodes, temporarily reduced postoperative neck traction sensation, and less anterolateral chest pain/numbness. Thus, GTSA-ET represents a safe, effective, and aesthetically preserving surgical option for patients with PTC.</p> Trial registration <p>Chinese Clinical Trial Registry number, ChiCTR2400086466. Retrospectively registered on 02/07/2024.</p>