Despite growing interest in gasless endoscopic unilateral thyroid lobectomy via the axillary approach, there are a lack of sufficient data on its safety and cosmetic outcomes. This retrospective study analysed the clinical outcomes and postoperative complications of 161 patients who underwent this surgery for thyroid cancer and nodules, with particular attention given to complications and patient satisfaction with cosmetic outcomes. All 161 patients (143 females, 18 males) successfully underwent the operation without conversion to open surgery. Temporary vocal cord paralysis occurred in five patients, with no other serious complications observed. The cosmetic outcomes were generally good, with no recurrences or tumour implantations observed during follow-up. For carefully selected patients, gasless endoscopic unilateral thyroid lobectomy via the axillary approach is not only safe but also provides excellent cosmetic results.