Mostly the ectopic ureter belongs to the upper pole in urinary tract duplications. In the pelvis, the two ureters are clearly separated. The only dissection of the ectopic ureter is in no case dangerous for the ureter of the lower pole. Therefore the reimplantation of the ectopic ureter can be performed separately. This only reimplantation of the ectopic ureter has been performed 9 times, without any mortality nor morbidity. The scar is almost invisible and the child is cured without any risk for the upper pole and saving the whole of the renal parenchyma. If the upper pole is functional, which happened in 1/4 of the cases, this technique is the best way and the less dangerous to recovery.