BACKGROUND: Urolithiasis is an actual problem of urology. Over the past 20 years, the tactics of treating patients with urolithiasis has changed significantly. However, there are currently no standardized algorithms for choosing the most effective treatment for a particular patient.
 AIM: To evaluate the efficacy and safety of using a mininephroscope in comparison with the use of a flexible ureterorenoscope when performing percutaneous antegrade ureterolithotripsy in the treatment of patients with proximal ureteral calculi.
 MATERIALS AND METHODS: A retrospective analysis of case histories of 61 patients with calculi in the proximal ureter was performed. All patients for surgical treatment were hospitalized in a planned manner with a previously installed nephrostomy drain 12Ch. All patients underwent percutaneous antegrade ureterolithotripsy 15 using a mininephroscope (Group 1) and 46 using a flexible ureterorenoscope (Group 2).
 RESULTS: The clinical performance of the mininephroscope and the flexible ureterorenoscope for ureterolithotripsy is similar. In patients of the 1st and 2nd groups, the average duration of the operation (59 10 min and 63 9 min, respectively, p 0.1) and the Stone Free Rate (SFR) on the first day after surgery (respectively 93.3% and 95.7%) did not significantly differ. There were no intraoperative complications in any of the patients. The frequency of postoperative complications in patients of the 1st and 2nd groups was low, all complications corresponded to the 1st degree according to the ClavienDindo classification. The duration of postoperative hospital stay in patients of the 1st and 2nd groups was the same and averaged 3 days.
 CONCLUSIONS: Performing percutaneous antegrade ureterolithotripsy using a nephroscope and a flexible ureterorenoscope ensures the achievement of SFR in the same short time, the minimum duration of surgery and the duration of the postoperative bed-day, as well as a low incidence of postoperative complications.