Abstract： Background Video-assisted thoracic sympathetic block is an effective,safe,and minimally invasive method fortreatment of primary hyperhidrosis.The purpose of this study was to decide which one of using electrocautery hook and titanium clip is the appropriate procedure for primary palmar hyperhidrosis by assessing the compensatory sweating (CS)and quality of life (QOL) of patients after sympathetic block.Methods Between October 2007 to August 2010,120 patients with primary palmar hyperhidrosis were randomly divided into two groups,electrocautery hook group (60 patients) and titanium clip group (60 patients).All patients were treated by sympathetic block at T4 level.The CS was graded based on severity and location; the QOL was classified to 5 different levels based upon the summed total scores (range from 20 to 100) before and after surgery.The variables were compared.Results The postoperative follow-up period was 2 months.All patients were cured.Three patients in electrocautery hook group and 1 patient in titanium clip group had a unilateral pneumothorax on chest X-ray,but none of them was necessary to have chest drainage.Neither perioperative mortality nor serious complications such as cardiac arrhythmia or arrest were observed during the operation.No bradycardia or Horner's syndrome occured.CS was not more common in patients in titanium clip group than in those in electrocautery hook group (P=0.001).Moderate and severe CS was few in all patients,and there was no significant difference between two groups (P=-0.193).Most of the patients feel a notable improvement of the the QOL; nevertheless,there was no significant difference between the groups (P=0.588).Conclusions Both electrocautery hook and titanium clip used for sympathetic block at the T4 level are effective,safe,and minimally invasive for palmar hyperhidrosis.Because of the lower severity of CS and the similar improvements in the QOL after operation,we prefer to use of titanium clip for treating palmar hyperhidrosis.