Purpose: to present a new technique of one trocar assisted retroperitoneoscopic Anderson-Hynes dismembered pyeloplasty in infants and children with ureteropelvic junction obstruction based on the clinical experience. Patients and Methods: From 1/2011 to 6/2013 seventy childrens (65 males
5 females) from 1 months to 5 years olds (mean age 22,9 + or - 18,6 months) underwent surgical treatment for ureteropelvic junction obstruction. The retroperitoneal space was entered via a 1,5 cm longitudinal incision beneath the 12th rib. The ureteropelvic junction was isolated with 1-port retroperitoneoscopy assisted. The ureteropelvic junction was exteriorized and a Anderson-Hynes dismembered pyeloplasty performed in an open fashion with double J stenting. Results: In 48 cases (68,57 percent) the obstruction was on left side and 22 cases (31,43 percent) on right side. 50 percent patients have the diagnosis antenatal. Mean diameter of pelvic is 34,3 + or - 8,1mm. In 2 cases the conversion to open surgery were required. Mean operative time was 74,8 + or - 15,2 minutes (45-100 minutes). No intraoperative complication and postoperative urinary lekage occurred. Mean hospital stay was 3,7 + or - 2,5 ngay. 53/70 (75,71 percent) patients have follow-up for 6-12 months, 17/70 (24,29 percent) patients have lost I follow-up. 2/53 patients were redone because of anastomose stenosis. Discussion and Conclusion: in the opinion the one trocar retroperitoneoscopic Anderson-Hynes dismembered pyeloplasty could be considered as a safe and feasible alternative to retroperitoneoscopic pyeloplasty, especially in small children.