During the past year we have used the thoracoscopic approach in performing bilateral upper dorsal sympathectomies for the treatment of palmar hyperhidrosis. We present our first 16 patients. Histological examination proved that sympathetic ganglia had been resected in all 32 procedures. Immediately after operation all hands were completely dry and 31 of them remained so on follow-up 5 months later (97% success rate). The main operative complications were bleeding in 3 cases (9.4%; only 1 severe), and chest and back pain for more than 1 week in 8 (50%). The main late sequela was compensatory hyperhidrosis of the chest and back in 10 cases (62%).