The goal was to review results of sympathectomy, performed with use of either cauterization or clamping, in patients with hyperhidrosis (n = 1,312): 653 early patients undergoing electrocautery sympathectomy, 305 later patients, undergoing cauterization, and 354 patients treated with a clamping procedure. Patients were interviewed by telephone about the status of symptoms, adverse outcomes, and satisfaction. Palmar hyperhidrosis was cured in all but one patient, with a 98% satisfaction rate in the clamping group and 94.3% and 95. 1 % in the two cauterization group, (P less than or equal to 0.025, clamping > cauterization). Facial sweating or blushing was cured in the majority (88%) of the 301 patients reporting this symptom. Severe compensatory hidrosis occurred in less than 6% (3% of the clamping group; P less than or equal to 0.001, clamping < cauterization). Recurrence rate was 3.0%. A number of factors were related to outcome. Endoscopic thoracic sympathectomy with clamping appears to be at least as safe and effective as earlier cauterization techniques, with the potential advantage of reversibility in those patients unhappy with the outcome.