Objective: Dismembered pyeloplasty through dorsal lumbotomy to correct ureteropelvic junction obstruction is mainly successfully performed in children under 5 years old for technical reasons. We compared children who underwent dorsal lumbotomy by age group (<5 vs. ≥5 years old) to determine if the surgical success and long-term results were comparable. Materials and Methods:We retrospectively reviewed the charts of 134 children undergoing a pyeloplasty. Group 1 consisted of children <5 years old (n = 90) and Group 2 consisted of children ≥5 years old. Patients' characteristics, as well as hospital stay, narcotic use, radiologic follow-up and success rate, were compared. Success was defined by absence of symptoms and ≥50% reduction in renal pelvis anteroposterior diameter and/or scintigraphic normalization of the drainage T1/2 when obtained. Univariate analysis was performed to compare the groups. Results: Mean age (years) and weight (kg) at surgery for Groups 1 and 2 were 1/8 kg and 11/35 kg, respectively. Mean operative time was 98 minutes versus 120 minutes, respectively; mean hospital stay was 2.5 days for both groups and analgesia requirement was 50% higher in Group 2. A Pippi-Salle stent was used in 90% (n = 120) of cases. Mean follow-up was 26 months and the success rate was 89% and 90% for Groups 1 and 2, respectively. Conclusion: Our study showed comparable success rates. We can infer that, as a technique, dismembered pyeloplasty is effective and safe in the younger and older children.