Ureteropelvic junction obstruction and duplicated collecting system are common urologic anomalies in upper urinary system, but they seldom occur in combination. These obstruction can occur in both partial or complete duplicated collecting system. Complete duplication of the ureter may be asymptomatic or recognized when complications develop as a result of reflux into the lower pole ureter or obstruction of the upper pole with an ectopic ureterocele. It is difficult to choose an optimal therapy due to the high variability in function, degree of obsturction, damage and potential for regeneration in growing kidney. We report our experience of successful surgical interventions in the ureteropelvic junction obstruction of the lower pole with complete duplicated collecting system.