Obstructive megaureter is shown by ureteral dilatation most frequently due to an obstacle at the level of ureterovesical junction. The obstacle is caused by a stenotic tract and/or the absence of peristalsis. The diagnosis of primary obstructive megaureter is usually prenatal. The pediatric surgeon together with the pediatric radiologist and nephrologist should pose the indication for surgery. The main criteria on which this approach should be indicated are the grade of megaureter and the renal function. Megaureters of low-mid grade should be followed by a "wait and see" approach because they may resolve spontaneously, while megaureters of high grade should undergo operative repair and ureterovesical reimplantation. Results are good with a low rate of complications (recurrence of stenosis or vesicoureteral reflux).