We report 6 instances of complete ureteral avulsion in 5 patients undergoing acute acceleration/deceleration trauma. One patient also had an unsalvageable contralateral renal arterial intimal injury. In all instances the ureteral avulsion injury was repaired successfully and in 4 patients only 1 surgical procedure was used. The injury, occurring primarily in children, seems to result from a sudden hyperextension of the trunk and the ureteropelvic junction appears to be the most susceptible to disruption injury. From our experience and from that of others, despite the occult nature of this injury and its tendency to be obscured further by associated injuries of greater immediate importance, persistence in diagnostic pursuit and surgical repair even when delayed will yield a satisfactory result.