The thoracoscopic technique has simplified surgery on the upper thoracic chain. This comparatively minimally traumatic approach has resulted in a pronounced increase in the number of procedures. The effect of ETS on severe palmar hyperhidrosis and facial blushing is very good. These conditions often cause social, professional and emotional handicaps. Side-effects, especially compensatory sweating (increased sweating on the trunk and legs), can, however, be severe. The procedure should be used only when the hyperhidrosis or facial blushing is severely detrimental to the quality of life. The expected effects, side-effects and risks for complications must be made clear before patients are accepted for ETS.