This study reports our experience of using thoracoscopic cervicodorsal sympathectomy with diathermy. From December 1994 to September 1998, we performed 53 thoracoscopic sympathectomies in 35 patients. There were 15 men and 20 women, ages 18 to 61 years. Ten surgeries were performed on the right side, 7 were the left, and 18 were bilateral. Indications for surgery were causalgia/reflex sympathetic dystrophy in 8 patients, Raynaud's/vasculitis in 6, intractable Raynaud's disease in 4, and hyperhydrosis in 17 (bilateral procedure). Operating time ranged from 10 to 50 min for unilateral procedures and from 45 to 80 min for bilateral procedures. Patients stayed in the hospital 1 to 4 days. From favorable immediate and follow-up results we conclude that thoracoscopic cervicodorsal sympathectomy using diathermy is feasible, safe, and effective.