In cases in which a portion of ureter is either accidentally or intentionally sacrificed, a difficult surgical problem presents itself. If the missing segment is short, end-to-end ureteroureteral anastomosis or ureteroneocystostomy may be satisfactorily completed. When an appreciable length of ureter is sacrificed, however, the remaining ureteral segments may be too short to permit mobilization and anastomosis without tension. If the bladder and kidney are normal, maneuvers such as ligation of the proximal end of the ureter, with or without subsequent nephrectomy, formation of a cutaneous ureterostomy, or ureterocolic anastomosis are undesirable for many reasons. Experience with ileal pouches created as substitute bladders suggested the use of an isolated segment of ileum as a substitute ureter interposed between the bladder and the proximal portion of ureter in order to maintain continuity of the urinary tract if a fairly long segment of ureter is missing. The feasibility of this procedure is