Objective To investigate the safety and feasibility of flexible ureteroscope/holmium laser therapy of parapelvic cyst complicating with renal calculi.Methods The clinical data of 8 patients diagnosed as parapelvic cyst with renal calculi and hospitalized in our hospital from Nov.2012 to Nov.2014 were retrospectively analyzed.They were 5 males and 3 females,aged 54 78 years,with an average of 63 years old.The largest kidney calculis were at the size of (1.2 cm× 1.1 cm) to (1.5cm×2.0 cm),and the size of parapelvic cysts ranged between (3.2 cm×3.6 cm) and (5.1 cm×4.2cm).Waist pain was found in 6 patients,hematuria in 3 patients,hydronephrosis in 1 patient,circumscribed hydrocalycosis in 2 patients,hypertension in 3 patients,and infection of urinary tract in 3 patients.Incision and internal drainage of parapelvic cyst and lithotripsy for renal calculi were conducted by flexible ureteroscope/holmium laser under general anesthesia.Results All of the 8 patients had successful operations without any complications such as massive haemorrhage,pararenal hematoma,extravasation of urine,infectious shock and kidney atrophy during or after the operation.The operation time ranged between 52 to 120 minutes,with the average of 76 minutes.All patients showed no residual renal calculus during a follow-up period of 3 to 12 months.Renal cysts were disappeared in 6 patients,and the size of renal cysts was significantly decreased in the other 2 cases.No parapelvic cyst and renal calculus recurred during the follow-up.Conclusions Flexible transurethral ureteroscope/Holmium laser therapy is a good method with the advantages of minimal trauma,quick recovery,simple operation,economic,safety and effectiveness in treating parapelvic cyst complicating with renal calculus.