Transureteroureterostomy creates an artificial ureter bifidus. In the common branch, the resting pressure is a little bit higher than in its bifurcation and the peristalsis of the bifurcation is never synchronous. That is why an ureteroureteral reflux may be produced by the anastomosis. The ureteroureteral reflux created by a ureteral dyskinesia, however, causes an infection in the recipient kidney only if there is a predisposition to infection or a vesicoureteral reflux in the recipient ureter. A transureteroureterostomy was performed on five female patients suffering from unilateral distal damage of the ureter, four of them after gynecologic operations. One patient had a single kidney right. The damaged ureter was anastomized with the left ureteral stump of the nephrectomied side. In one case, an abscessing retroperioneal urinoma with a serious diffuse peritonitis developed as a direct complication of the operation because of an insufficient suture. On revision, the transplanted ureter had to be drained into the skin. Despite this serious complication, the recipient ureter remained uninjured and the recipient kidney was not damaged. The four other patients had no complications.