Large meta-analyses demonstrated that ureteral access sheaths (UAS) have specific complications during and after flexible ureteroscopy (fURS). The present study focused on the technical aspects, advantages, drawbacks, and limitations of the latest “no-touch” technique (NTT) in the flexible ureteroscopic therapeutic approach of renal stones. A total of 288 patients with a single pyelocaliceal stone (largest diameter between 11 and 29 mm) underwent fURS: 144 using the 12/14 Fr UAS (group 1) and 144 without UAS (group 2). For NTT, we used four types of ureteroscopes: Olympus URF-V2 (8.5 Fr) – 33 cases, Storz Flex X2 (8.4 Fr) – 60 cases, single-use PUSEN PU 3022 (9.5 Fr) – 37 cases, and single-use PUSEN – PU 3033A (7.5 Fr) – 14 cases. For group 1, we used the Olympus URF–V2 ureteroscope in 44 cases, the Storz Flex X2 in 58 cases, and the single-use PUSEN PU 3022 in 42 cases. We compared the operative time, hospitalization periods, and complications. Successful access sheath insertion was noted in 83.3% of cases from group 1, and successful ureteroscope insertion was noted in 90.9% of cases from group 2. The average operative time was slightly higher in group 1 vs. group 2 (47 vs. 39 min). Stone-free rates (SFRs) were overall lower in group 2 (76.3% vs. 86.8%) at 1 month. At 3 months, we did not find a significant difference between these two groups. Superficial mucosal ureteral wall lesions were found in 38.8% of patients from group 1 and 4.1% from group 2. Hospitalization periods were longer in group 1 vs. group 2 (21 vs. 29 hours, respectively). The single-use 7.5 Fr ureteroscope should receive a special mention: the insertion was simple, we did not encounter any mucosal ureteral wall lesions, and all patients were discharged on the same day. Despite the clear advantages of routine UAS usage, there are many adverse events for the patient. Larger diameter sheaths involve a greater risk of ureteral wall injury. NTT seems to improve peri- and postoperative safety while preserving therapeutic efficiency. The new 7.5 Fr ureteroscopes appear to optimize surgical efficiency and diminish complications in the flexible ureteroscopic treatment of renal stones.