Following construction of a continent colonic urinary reservoir, 5 uretero-colonic reimplantations became obstructed at the anastomotic site. In these obstructed units previous percutaneous balloon dilation and stent placement had failed and they were subsequently treated by a new reimplantation procedure. Preoperatively, in all ureteral units a percutaneous ureteral stent was inserted to facilitate intraoperative recognition of the ureteral meatus. The technique included a trans-reservoir approach, which allowed easy localization of the stent and anastomotic site. The ureter was dissected free from the intestinal wall and then was mobilized into the lumen of the reservoir. After excision of the scarred distal ureteral segment and spatulation of the proximal healthy ureter, a new direct mucosa-to-mucosa reimplantation was performed leaving the ureter stented. This trans-reservoir approach (occasionally done through an abdominal transverse muscle splitting incision) allows for shortening of the operation, and avoids the time-consuming and more complicated transabdominal lysis of adhesions. All newly reimplanted ureters (100 percent) showed evidence of adequate ureteral drainage without residual obstruction on followup excretory urography or furosemide renography up to 45 months postoperatively. The trans-reservoir approach for refractory ureteral reimplantation obstruction in continent colonic reservoirs has been associated with no morbidity or mortality, and facilitates the solution to a difficult clinical problem.