OBJECTIVE: To investigate the efficacy and safety of endoscopic transverse carpal ligament release using the double-entry Chow method with a transparent external catheter in the treatment of carpal tunnel syndrome. METHODS: Twenty-three wrists of 16 patients with carpal tunnel syndrome treated by double-entry Chow method with a transparent external catheter at Peking University First Hospital from July 2008 to April 2012 were selected. There were 2 males and 14 females; the mean age was 53.19 years (25-62 years); 13 cases were right wrist, 10 cases were left wrist, and 7 cases were double wrist. The surgery was performed with local anesthesia, tourniquet, and double incision at the wrist, approximately 5 mm, with the transverse carpal ligament incised and the median nerve released in a transparent external catheter where the tendon, ligament, and nerve could be distinguished. Results: The average operative time for single wrist was 15 min, with 0 ml of bleeding. 2 to 39 months of postoperative follow-up, with a mean of 25.19 months. Five cases were lost, and a total of 18 wrists were followed up. There were no postoperative complications such as median nerve, blood vessel, tendon injury and nerve adhesions, no secondary surgery and no aggravation of symptoms. There were no skin deep or superficial sensory disorders and no painful incisional scar. Grip strength and pinch strength were improved to different degrees. The postoperative Kelly grading: excellent in 9 cases, good in 7 cases, fair in 2 cases, and poor in 0 cases. The excellent rate was 88.9%. The two cases with fair grading were among those with preoperative Hamada classification grade III. Conclusion: The arthroscopic “double orifice” Chow method of transverse carpal ligament release with a visualized transparent cuff has a small skin incision, minimal tissue trauma, and a short operative time, and the patient can be discharged on the same day. The operation does not require external fixation in plaster, and no large surgical scar remains, avoiding complications such as scar pain and limited function of the wrist joint. Contraindications: Wrist fracture deformities, cysts, tumors, secondary release, suspected adhesions in the carpal tunnel