BackgroundTo report current worldwide variation in techniques and clinical practice of flexible ureteroscopy (FURS) among endourologists of different case volumes per year.MethodsTwo invitations to complete an internet survey were emailed to Endourological Society members. Some of survey questions asked about indications of using FURS for renal and upper ureteral stones. Others were concerned with clinical practice of FURS (such as preoperative stenting, use of ureteral access sheath (UAS) and safety guidewire, technique of Laser lithotripsy and fragment retrieval, and post-FURS stenting. Responders were distributed into two groups; high-volume (> 100 cases/year) and low-volume surgeons (< 100 cases/year) and data were compared between both groups.ResultsResponses were received from 146 endourologists all over the world (62 high-volume and 84 low-volume). FURS for intrarenal stone > 20 mm was used by 61% of high-volume surgeons compared with 28.6% for low-volume (P < 0.001). Semirigid URS was used for upper ureteric stones in 68% among high-volume group and 82% in low-volume group (P = 0.044). UAS was used by 62% in low-volume group and 69% in high volume group (P = 0.516). Laser stone dusting was preferred by 63% in low-volume group versus 45% by high-volume (P = 0.031). More responders in low-volume group preferred to leave the stent for 6 weeks (P = 0.042).ConclusionsThe use of FURS for treating upper tract calculi has expanded by high volume endourologists to include large renal stones > 20 mm. Low-volume surgeons prefer to use semi-rigid URS for treatment of upper ureteral stones, to apply Laser stone dusting and maintain ureteral stents for longer periods.