Purpose: The efficacy of endoscopic injection of dextranomer/hyaluronic acid to correct primary vesicoureteral reflux is well documented. We present experience at 2 institutions with endoscopic treatment for vesicoureteral reflux after failed ureteroneocystostomy. Materials and Methods: A retrospective review was performed of the records of all patients who underwent endoscopic dextranomer/hyaluronic acid injection to correct vesicoureteral reflux following ureteral reimplantation between April 2002 and July 2005. De novo ipsilateral vesicoureteral reflux was noted after repair of primary nonrefluxing megaureters or renal transplantation and persistent vesicoureteral reflux was noted following attempted vesicoureteral reflux repair. Injection was performed using the standard technique if the ureteral orifice was easily accessible, and percutaneously if access was difficult. Results: Nine male and 9 female patients were identified. Median age was 1.9 years at reimplantation and 6.5 years at injection, and median followup was 19 months. Ten patients underwent extravesical detrusorrhaphy and 8 underwent cross-trigonal reimplantation. Six patients underwent reimplantation for primary megaureter repair and all had resolution of vesicoureteral reflux with injection. Of the 20 renal units 16 (80%) and 15 of 18 patients (83%) had complete resolution of vesicoureteral reflux after 1 injection. One patient had improvement in vesicoureteral reflux and 2 had no improvement. There were no complications resulting from injections. Conclusions: Endoscopic treatment of vesicoureteral reflux with dextranomer/hyaluronic acid following extravesical or cross-trigonal reimplantation is safe and efficacious, at least at short-term followup. Endoscopic injection should be considered first line treatment for this situation. © 2006 American Urological Association.