OBJECTIVE Many institutions have reported varied levels of success with ureterocystoplasty. Recently, there have been concerns regarding the efficacy of ureterocystoplasty as a form of bladder augmentation. We report our long-term functional outcomes with the procedure based on the experience of a single surgeon. METHODS A total of 17 procedures were performed during a 12-year period. Of the patients 10 had posterior urethral valves, 3 had bladder exstrophy, 2 had a neuropathic bladder, 1 had a cloacal anomaly and 1 had a left ectopic ureter. Mean patient age at operation was 5.9 years (range 0.3 to 14.2). All patients underwent preoperative ultrasound, urodynamic studies and radionuclide scanning. Postoperative urodynamics were performed at 6 months. RESULTS Followup ranged from 0.5 to 11.5 years (mean 4.5). Nine patients underwent ureterocystoplasty with preservation of the ipsilateral kidney, and 1 underwent ureterocystoplasty alone and had a solitary right kidney. The remaining 7 patients underwent ureterocystoplasty with ipsilateral nephrectomy. Postoperatively, the mean bladder capacity improved from 125 to 292 ml, while the mean end filling pressure decreased from 72 to 22 cm H(2)O. Mean preoperative system compliance was 2.1 ml/cm H(2)O, which increased to 16.2 ml/cm H(2)O postoperatively. A total of 13 patients did not require further augmentation surgery. The remaining 4 patients had high pressure and poorly compliant bladders, and underwent ileocystoplasty. Subsequent postoperative nucleotide scans in these 4 patients demonstrated stable upper tracts with good drainage. CONCLUSIONS Based on our results, ureterocystoplasty provides durable functional urodynamic improvement in patients with a megaureter.