OBJECTIVE To describe a modified technique for easily locating cystic wall during flexible ureteroscopic surgery for treatment of parapelvic renal cysts. METHODS Nineteen patients with symptomatic/asymptomatic parapelvic renal cyst were treated with modified or conventional flexible ureteroscopic surgery between February 2015 and March 2017, and the differences of the 2 techniques were compared. The detailed surgical procedures and results, postoperative complications, and patients' follow-ups were evaluated. RESULTS All the patients received endoscopic management by flexible ureteroscope successfully, without requiring another complicated surgery. The cysts were seen clearly in 9 patients with modified method. Two of ten patients who underwent conventional ureteroscopic surgery changed to the modified surgery intra-operatively since it was difficult to identify the cyst. The total time of search and incision of cysts was 24.2 +/- 6.2 minutes and 17.7 +/- 2.5 minutes for conventional and modified technique respectively (P = .01), of which 11.4 +/- 4.8 minutes and 5.1 +/- 1.1 minutes to search the cysts, respectively (P = .002), and the mean time of the procedure of puncture was 8 +/- 2.3 minutes. Duration of pure incising the cystic wall was 12.8 +/- 3.3 minutes and 12.6 +/- 2.5 minutes for patients who underwent conventional and modified technique, respectively (P = .859). All patients acquired relief from the presentation of flank discomfort after surgery. All of the patients were followed-up over 12 months and no serious complications and recurrence was observed. CONCLUSION The modified technique can decrease time of searching the renal cyst and decrease the total time in flexible ureteroscopic treatment of parapelvic cysts. The limitations of our study were also observed and further studies are needed. (C) 2018 Elsevier Inc.