The endoscopic thoracic sympathicolysis procedure is a chirurgical technique used in the treatment of the primary palmar hyperhidrosis.Descriptive and retrospective study of 25 patients with diagnosis of palm and palm-axilar hyperhidrosis surgically intervened in a period of 4 years in three private institutions of Gran Buenos Aires. The age ranged between 8-18 years. In all of the cases the surgery consisted in the endoscopic thoracic sympathicolysis of the T2-T3 ganglion. The operation was made in both sides and in one surgical time. There were considered for this study the age, sex, intra- and post-surgical complications, side effects, efficacy of the procedure and the grade of patients satisfaction.Hyperhidrosis disappeared in 98% of the patients. Besides the improvement of palmar excessive sweating, diminution of axilar perspiration was found in 16 patients, and in the feet in 6 patients. The rate of post-operating complications was 20% and all were transitory. Three patients showed a subcutaneous emphysema that resolved in 24-48 hours. One patient referred important pain 24 hours and one patient referred pain in the puncture zone that improved with common analgesic until it disappeared in three months. About the satisfaction with the procedure, 22 patients declared to be very satisfied, two were satisfied and one moderately satisfied.The primary palmar hyperhidrosis is a pathology that entails an important reduction in the quality of life of those who suffer it. The results obtained with this technique allow recommending the endoscopic thoracic sympathicolysis procedure for the treatment of this pathology in pediatrics.