A 26-year-old man suffered from hyperhidrosis palmaris since childhood. He had received bilateral transaxillary thoracoscopic T3 sympathectomy immediately after the operation weakness in right biceps, brachialradialis, deltoid, supraspinatus, and infraspinatus muscles and parathesia in right C5-6 dermatomes were noted. Serial neurological studies indicated a right brachial plexopathy. We placed the patient in a rehabilitation program from the third day after the surgery and he had a good recovery within 2 months. Video-associated thoracoscopic sympathectomy is an easy, safe, effective and timesaving procedure. Reported complications are few- and our case was related to positioning of the operation.