['To evaluate the outcomes of kidney stone treatment using flexible ureterorenoscopy (f-URS) among patients with chronic kidney disease (CKD).', 'Data of patients who underwent f-URS between January 2009 and December 2012 were collected. Patients were staged according to estimated glomerular filtration rate. Patients with stage ≥ 3 were accepted as having CKD (study group). These patients were matched with a group of patients without CKD (control group). Operative characteristics, complication rates, and third-month success rates were compared.', 'Overall, 339 patients underwent f-URS and 62 (18.28%) had CKD. Control group constituted of 87 patients. Having a solitary kidney (17.4% vs 3.5%; P = .003) and history of stone intervention (51.6% vs 23%; P = .001) were more common in the CKD group. Similarly, access sheath was more commonly used among patients with CKD (87.1% vs 70.22%; P = .015). Both perioperative (19.35% vs 19.54; P = .372) and postoperative (22.6% vs 16.1%; P = .214) complication rates were similar in patients with and without CKD. Hospitalization time was 25.70 ± 25.62 and 24.5 ± 25 hours (P = .871) for patients with and without CKD, respectively. Although mean third postoperative estimated glomerular filtration rate of patients with CKD did not change significantly (48.16 ± 8.72 vs 49.08 ± 9.26; P = .431), CKD stage of 13 patients shifted from 3 to 2. At the third postoperative month, stone free rate in patients with and without CKD was 87.1% vs 86.2% (P = .875).'] Is flexible ureterorenoscopy safe and efficient for the treatment of kidney stones in patients with chronic kidney disease?