Background: Different types of stents are used in pyeloplasty and those include either an double-J (DJ) or an externalized stents. The aim of this work to explore the outcome of using internal DJ versus external nephroureterectomy tube following open pyeloplasty in children with primary Ureteropelvic Junction Obstruction(UPJO) emphasizing the advantages and drawbacks of its use and the outcome of pyeloplasty with both types of stents. Methods: This prospective single center comparative interventional study was carried out on 60 patients, pediatric age to 18 years old, with primary UPJO. Patients were divided into two equal groups: Group 1: patients underwent antegrade DJ stent insertion, group 2: patients underwent placement of external stent. Results: There was a statistically significant difference between groups regarding hospital stay, median stent duration, stent migration, Prolonged drainage, Urinary tract infection symptoms, leakage, split function at 12 months follow upand stent cost. There was no statistically significant difference between groups, regarding median operative time pyelonephritis, urinoma, fever, obstruction, anterior-posterior renal pelvic diameter after 3, 6,12 months, parenchymal thickness at 3,6,12 months, glomerular filtration rate at 6,12 months follow up, split function at 6 months follow up, t1/2 at 6,12 months. Regarding Success rate 28 patients had a succeeded operation in the External stent group, and 27 patients had a succeeded operation among the DJ stenting group. Conclusions: Both types of stents demonstrated similar success and complication rates,although DJ stent insertion provides a shorter hospital stay than the external stent and external cost less than DJ stent