The purpose of this study was to identify parameters that affect fluoroscopy time during ureteroscopy or retrograde intrarenal surgery (RIRS) and to evaluate the potential role of surgical experience gained during a fellowship program in decreasing radiation exposure. A database of patients who underwent ureteroscopy or RIRS was evaluated. Procedures were performed either by an experienced Endourologist (surgeon A) or by an Endourology fellow. Operations performed by the fellow were further divided to them performed during fellow's 1st year of training (surgeon F1) and 2nd year of training (surgeon F2). The association between fluoroscopy time and several factors was evaluated. Eighteen (19.6%) procedures were performed by surgeon F1, 13 (14.1%) by surgeon F2 and 61 (66.3%) cases were performed by surgeon A. Fluoroscopy time was significantly higher in cases performed by surgeon F1 compared to surgeon F2 (p=0.025) and A (p=0.001). However, there was no difference between surgeon F2 and A (p=0.969). There was significant association between fluoroscopy time and obesity (p=0.023), stone size (p=0.009), surgical experience (p=0.001), procedure duration (p<0.001) and the insertion of a postoperative double-J stent (p<0.001). Multivariate analysis showed that procedure duration (p=0.003), postoperative stenting (p=0.009) and surgeon's experience (p<0.001) were all significant independent predictors of increased fluoroscopy time. Fluoroscopy time may widely vary during ureteroscopy and RIRS. Procedure duration, the insertion of a postoperative double-J stent and surgical experience are all independent predictors of increased fluoroscopy time.