Upper dorsal sympathectomy is the only successful therapeutic method for idiopathic palmar hyperhidrosis (IPHH). However, the techniques for sympathetic ablation are still debated. The aim of this study was to compare prospectively two accepted methods for endoscopic sympathetic ablation: resection of T2-T3 ganglia versus transection of the chain over the second to fourth ribs. During the period September 2000 to June 2002, a total of 32 patients with IPHH were operated on. Operations were performed under general anesthesia through two 5-mm trocars using electrocautery. Resection was done on one side and transection on the other, with both sides being addressed during the same operation. The sides of resection/transection were alternated at each operation. There were 14 men and 18 women aged 18.8 +/- 4.7 years. The mean operating times for sympathectomy were 12.0 +/- 3.1 minutes for resection and 6.6 +/- 1.9 minutes for transection (p = 1.38). All patients were examined at 2 weeks postoperatively and again at 1 month. During November-December 2005, patients were approached by telephone questionnaire, the mean follow-up period being 4.3 +/- 0.9 years. Altogether, 26 of the 32 patients could be located (15 women, 11 men). There was no significant difference with regards to perioperative complications, immediate or long-term pain. All but two hands were warm and dry 1 month after operation and remained so at follow-up. The exceptions included one hand with recurrent hyperhidrosis after 1.5 years and one that became less dry and cold at 3 years. Both were on the transected sides. Our results suggest that sympathetic resection may achieve slightly better long-term results than transection in patients with IPHH. Large-scale prospective studies are needed to confirm these results.