OBJECTIVE: Open dismembered pyeloplasty is considered the gold standard to treat ureteropelvic junction obstruction (UPJO) in children. Laparoscopic pyeloplasty (LP) and robot-assisted pyeloplasty (RAP) are increasingly popular. Our present protocol consists of using minimally invasive techniques for all children with UPJO. Here, we report our first 40 cases operated under this protocol. PATIENTS AND METHODS: Retrospective chart review of patients who underwent LP and RAP for UPJO between 2006 and 2010 was performed. Children younger than 4 years of age underwent LP and children aged 4 years and older with robot assistance. Results were assessed comparing pre- and postoperative imaging studies, operating time, hospital course and complications. RESULTS: Thirty-nine patients underwent 41 dismembered pyeloplasties (20 patients LP, 19 patients RAP). No conversions to open surgery were performed. The difference in operative time was statistically significant. The average hospital stay was 7 days (LP) and 6 days (RAP). All patients showed significant decrease of hydronephrosis and the overall success rate was 100%. The complication rate was 25% in the LP and 28% in the RAP group. CONCLUSION: Our data show that RAP and LP are effective to correct UPJO with similar outcomes and complication rates. None of the patients in this series required re-intervention to correct obstruction and the results are comparable with open surgery.