BACKGROUND: It has been known that the most effective treatment method of hyperhidrosis is video-assisted thoracoscopic sympathetic nerve block. Postoperative compensatory hyperhidrosis and anhidrosis are major factors that decrease the postoperative satisfaction. Although sympathetic rami have been selectively blocked to decrease the complications, technical difficulties and excessive bleeding have prevented the universal application. MATERIAL AND METHOD: Three pre-fixative cadavers were dissected before clinical application. Bilateral sympathetic chains were exposed in supine position after the whole anterior chest wall was removed. Second and third sympathetic rami were blocked using clips. After the sympathetic chains including ganglia were removed, we evaluated the extents of rami block. Twenty-five patients were subjected to the clinical application. Surgeries were performed in semi- fowlers position under general anesthesia and bilateral ventilation. 2 mm thoracoscopy and 5 mm trocar were introduced through third and fourth intercostal space, respectively. Second and third sympathetic rami were blocked using thoracoscopic clips. The postoperative complications, satisfaction, and compensatory hyperhidrosis rate were evaluated retrospectively. RESULT: Sympathetic rami were completely blocked in cadaver dissection study. Hyperhidrosis symptom was improved in all patients without operative complication. Operative time was shorter than that of traditional ramicotomy. All patients, except four, were satisfied with postoperative palmar hyperhidrosis. Compensatory hyperhidrosis was more severely happened in fifteen patients (60%). The remaining six patients had no complaint. Two patients had a minimal degree of gustatory hyperhidrosis. CONCLUSION: This operative method had shorter operative time and less complication rate, compared with traditional ramicotomy. Operative success rate was similar to the traditional sympathicotomy; lower extent and occurrence rate of compensatory hyperhidrosis. The thoracic sympathetic rami clipping was suggested as an alternative method for treatment of palmar hyperhidrosis.