Laparoscopic unroofing of renal cyst has replaced open surgical intervention in recent years. We report our experience with this procedure on 6 patients with hydronephrosis due to peripelvic cyst. Four male and two female patients, ranging from 51 to 67 years, underwent laparoscopic unroofing of peripelvic cyst. All patients had various degrees of hydronephrosis. Two patients had lumbago and hematuria. The cause of this hematuria was probably due to the renal pelvic stone. Surgical approaches i.e., retro- or transperitoneal were selected depending on the location of cyst. The operative time ranged from 80 to 235 minutes (mean 167 minutes). The length of postoperative hospital stay ranged from 3 to 7 days (mean 4.6 days). Intraoperative blood loss ranged from 20 to 26 cc (mean 21 cc). Four weeks after the operation, all patients showed improvement of hydronephrosis. Laparoscopic unroofing of peripelvic cyst is a safe and efficacious procedure, and could be an' attractive alternative for management of peripelvic renal cysts.