Introduction: The success of upper urinary tract endoscopy on one hand and the high cost of purchase and maintenance of the scopes on the other hand have driven the development of disposable digital flexible ureterorenoscopy (fURS). Materials and Methods:We performed an ex vivo comparison of 2 disposable digital fURS from different companies with a state-of-the-art reusable endoscope from another well-established scope manufacturer. The scopes were tested comparing parameters such as instrument handling, irrigation flow, image quality, and deflection. For the disposable scopes, the latter 2 were evaluated both, before and after vigorous stress testing. Results: Expectedly, the most consistent finding among the 3 instruments was the marked decrease on irrigation flow following insertion of a working element, most notably a guidewire. Depth perception and ergonomic handling were comparable in all 3 instruments.Poststress testing revealed a significant loss of upward deflection in both disposable instruments, more so when an auxiliary instrument is inserted into the working channel. However, this did not appear to be the case in downward deflection. Conclusions: To our knowledge, this is the first study that used a vigorous stress testing protocol comparing disposable and reusable fURS. The newer generation disposable scope fared better than the older one. Results are encouraging and indicate that improvements are ongoing and progressing, bringing the quality of disposable scopes to the level that we are used to from our reusable high performance scopes while at the same time avoiding costly damage repairs. Continuous research and evidence-based interpretation of results in the absence of commercial bias are paramount to ensure this ongoing development.