OBJECTIVE Paraureteral or Hutch diverticula are congenital bladder diverticula that occur at or adjacent to the ureteral hiatus and are associated with vesicoureteral reflux in the majority of cases. Surgical treatment has traditionally been ureteral reimplantation with or without diverticulectomy. We present our experience with endoscopic treatment of vesicoureteral reflux associated with paraureteral diverticula. METHODS Of 745 patients undergoing endoscopic treatment for vesicoureteral reflux between 2002 and 2006, 17 (2.3%) had paraureteral diverticula located at the refluxing ureter. The hydrodistention implantation technique was used and dextranomer/hyaluronic acid copolymer was used as bulking material. Success was defined as vesicoureteral reflux grade 0 on postoperative voiding cystourethrogram at 1 to 3 months after a single treatment. RESULTS A total of 20 refluxing ureters with associated paraureteral diverticula were treated in 17 patients. Of the cases 14 were unilateral and 3 were bilateral. Reflux was grade I in 6 patients, grade II in 4, grade III in 8, grade IV in 1 and grade V in 1. A mean of 1.2 ml bulking agent was injected per ureter. Overall success was 81% (13 of 16 patients) after a single injection. Success per vesicoureteral reflux grade was 100% (6 of 6 patients) for grade I, 100% (3 of 3) for grade II, 63% (5 of 8) for grade III, 100% (1 of 1) for grade IV and 100% (1 of 1) for grade V. Endoscopic treatment failed in 3 patients. Multivariate analysis identified large diverticular size and high bulking agent volume as predictors of treatment failure. Age, reflux grade and the presence of unilateral vs bilateral paraureteral diverticula did not impact outcome. CONCLUSIONS Endoscopic injection of dextranomer/hyaluronic acid copolymer is an excellent choice for the treatment of vesicoureteral reflux associated with paraureteral diverticula because it has a high success rate and avoids open surgery.