In this study, we aimed to investigate the effects of ureterorenoscopy (URS) on morbidity and renal functions in patients with ureteral stones and nondialysis-requiring renal insufficiency. The data of 3200 patients who had ureterorenoscopic lithotripsy and diagnostic URS were analyzed retrospectively. Age, urea and creatinine levels in the preoperative period and 4 h after surgery, the size of the stone, duration of surgery, percentage change in urea and creatinine levels [(last level-first level/first level) × 100] and postoperative complications were noted. Student's t-test was used for the intergroup analysis of continuous variables. p < 0.05 was considered as statistically significant. There were 90 patients in nondialysis-requiring renal insufficiency group (group 1) and 101 patients in the control group (group 2). Percentage changes of urea and creatinine levels in the renal insufficiency and the control groups were found as -0.3% ± 3.3, 0.67% ± 3.9 and 2.3% ± 23.2, 2.5% ± 31.6 (p = 0.24 and p = 0.56), respectively. In group 1, three (3.3%) patients had postoperative febrile urinary infection, however febrile infections were not seen in any of the patients in group 2 (p = 0.06). Our results indicated that URS might be used safely in ureteral stones of the patients with nondialysis-requiring renal insufficiency.