Objective:To evaluate the safety and efficacy of endoscopic cryoablation (ECA) in patients with upper tract urothelial carcinoma (UTUC).Methods:The clinical data of 9 patients with UTUC treated with ECA from April 2018 to September 2019 were retrospectively analyzed. Patients consisted of 3 males and 6 females, with median age of 76 years old (ranging from 50 to 88 years old). Among the patients, 6 cases had tumors of ureter, 1 case had tumor of renal pelvis and 2 cases had tumors of renal pelvis combined with ureter. Of the 9 patients, two had bilateral UTUC, six were presented with single lesion, three were presented with multiple lesion. The size of tumors were (1.53±0.91)cm. The tumors of all cases were localized (≤stage T 2), and there was no carcinoma or suspicious lymph node/distant metastasis. All patients enrolled in this study had strong will to choose kidney-sparing therapy. Biopsy, resection of intraluminal lesion with laser and cryoablation under ureteroscopy or percutaneous nephroscopy was performed under general aneasthesia.Ureteroscopy was performed 3 months after cryoablation. Perioperative complications and follow-up results were recorded and assessed. Results:Cryoablation was successfully performed in patients under ureteroscopy (n=8) or nephroscopy (n=1). The median cryoablation time was 6 (ranging from 4-16) minutes. The median follow-up was 16 months (ranging from 4-24 months). No tumor recurrence was observed at primary sites during follow-up. Two patients with multiple lesions were observed denovo ureteral neoplasms outside the primary sites 3 months and 6 months after cryoablation and treated with second cryoablation. One case died due to cardiovascular events 4 months after surgery. One patient underwent ureteral stricture during follow-up and received ureteroscopic balloon dilatation. No recurrent stricture was found in this case during the subsequent follow-up of 16 months. The other 5 cases showed no recurrence or complications like stricture during follow-up.Conclusions:ECA could probably be a promising treatment for localized UTUC. No recurrence in primary site and low incidence of ureteral stricture was observed during follow-up. The efficacy and safety of ECA need to be verified with large sample study.