Background: Recurrent PUJO after index pyeloplasty is rare and has traditionally been suspected based on symptoms including flank pain and vomiting. However, some children may develop recurrent obstruction and loss of function whilst asymptomatic. The frequency of “silent” recurrent PUJO, and its association with loss of renal function remains poorly defined. Methods: We undertook a 25-year retrospective review of all redo pyeloplasties for recurrent PUJO performed at The Children’s Hospital at Westmead. Cases with concomitant obstructive uropathy or incomplete radiological data were excluded. Symptom status at the time of redo surgery and surveillance USS and MAG3 renography data were analysed. Results: Between 2000 and 2025, twenty children underwent a redo pyeloplasty (85% male, 70% left PUJO). Ten children (50%) were asymptomatic at the time, representing silent recurrent PUJO. The remaining 10 children developed one or more symptoms: significant vomiting (5), recurrent ipsilateral flank pain (4), urosepsis (2), distention with a palpable abdominal mass (2) and new hypertension (1). Four children developed symptoms suggestive of obstruction within 72 hours of stent removal. The median time from pyeloplasty to redo pyeloplasty was 5 months (IQR 3.4 – 11.1), with 80% of redo pyeloplasties occurring within 12 months. Prior to redo pyeloplasty, 88% of children had worsening hydronephrosis (median Δ APD +8.0mm (4.0 – 16.0), and 90% children had a loss of renal function on MAG3 (median Δ DRF -10.5% (-22.5 to -7.5)). Clinically significant loss of renal function (>10%) occurred in 50% of both symptomatic and asymptomatic children. Conclusions: Recurrent PUJO is asymptomatic in 50% of cases and can be associated with loss of renal function. Symptom status alone is not a sufficient discriminator of children at risk of functional decline, and hence, early structured imaging surveillance following pyeloplasty is essential.