Objectives: to study the indication and evaluation of early results of treatment of ureteropelvic junction obstruction in newborn and suckling. Methods: Descriptive, retrospective studySubjects: 23 newborns diagnosed with ureteropelvic junction obstruction were treated at Pediatric Surgery Department in Viet - Duc hospital from January 2005 to July 2009.Results: 20 among 23 cases were antenatally diagnosed, eight of them have bilateral hydronephrosis.