Background <p>Since the evolution of flexible ureteroscopy from being reusable to disposable then reused disposable scopes aimed basically to reduce the cost, this study was conducted to evaluate the causes of reused single-use flexible ureteroscope damage in order to extend its longevity and increase the number of procedures per scope.</p> Patients and methods <p>This retrospective study was conducted in a single center between September 2022 and September 2024. Sixty-two reused single-use flexible ureteroscopes after resterilization were used for 202 patients over 235.7&#xa0;hours. Potential causes of scope damage were observed, recorded and analyzed.</p> Results <p>The observed causes of reused single-use flexible ureteroscope damage were as follows: 32.3% of scopes were damaged by laser fiber related damage (either by sudden withdrawal of fiber during firing or transmitted energy), 27.4% by sustained excessive deflection, 19.4% by scope backloading technique, 9.6% by traumatic ureteral access sheath usage (such as scope withdrawal while deflected over the access sheath and stone fragment lodgment between the sheath and scope) and 11.3% by instrumental working channel damage. On comparing different related causes of damage, fine deflection proved to be superior to excessive deflection (<i>p</i> &lt; 0.001) and access sheath usage proved to be significantly superior to backloading (<i>p</i> = 0.005) while there was no significant difference on comparing laser settings.</p> Conclusion <p>Longevity of single-use flexible ureteroscope can be extended by avoiding potential causes of damage. Cost-effective practice can be achieved through careful scope handling, use of ureteral access sheath instead of backloading, relocation of lower calyceal stones, and proper laser fiber management.</p>