Background: Palmar hyperhidrosis (PH) hinders daily activities and deteriorates quality of life (QOL).Endoscopic thoracic sympathicotomy (ETS) is safe and efficient as the gold standard treatment for PH.So far, the long-term change of QOL after surgery has not been fully characterized, which is important to evaluate clinical benefits and helped to identify the true beneficiaries. In the current study, we aimed to investigate the long-term outcome of ETS by comparing their preoperative QOL with a follow-up QOL. Methods: This study enrolled 367 patients with PH who underwent ETS between March 2018 and March 2019. All patients were surveyed by a web-based questionnaire adapted from de Campos Quality-of-life Questionnaire for Evaluation of Hyperhidrosis, and compared to their preoperative results. Results: After a median follow-up of 14 months [interquartile range (IQR), 9-21 months], improvement in QOL was reported in 90.7% of patients. Compared to preoperative QOL [median (Md) =40, IQR, 37-45],postoperative QOL was significantly improved (Md =20, IQR, 13-23; P<0.001). A higher QOL score was noticed in patients with severer PH at diagnosis, whereas no significant difference was observed among postoperative QOL regarding the severity of PH. Subclinical compensatory hyperhidrosis (CH) occurred in 94.6% of post-ETS cases after long-term follow-up. The score of postoperative QOL was significantly positively correlated to the severity of CH (rs=0.14; P=0.009).Conclusions: Improvement in QOL sustained for a long-term period after receiving ETS for PH. Almost all patients developed subclinical CH on other body sites in the long run, with an impairment in QOL correlating with the severity of CH. Further investigations on the developing patterns of CH and clinical coping strategy are warranted to improve the long-term outcome of ETS.