Ureteral injuries are uncommon and challenging. In this study we report our institutional experience with ureteral injuries. We evaluated the American Association for the Surgery of Trauma-Organ Injury Scale (AAST-OIS) for ureteral injuries as a predictor of outcomes for complexity of repair, morbidity, mortality and associated injuries. We performed a retrospective, 120-month study (January 1992 to December 2002) at an urban, level I trauma center. In the 57 patients mean hospital Admission blood pressure +/- SD was 115 +/- 25 mm Hg, mean Revised Trauma Score was 7.38 +/- 0.84 and mean Injury Severity Score was 15 +/- 1.15. The mechanism of injury was penetrating in 55 cases (96.5%), including gunshot wound in 52 (54.5%) and stab wound in 2 (5.5%), and in blunt 2 of motor vehicle accidents (3.5%). The anatomical location was the left side in 33 cases (58%), right side in 23 (40%) and bilateral in 1 (2%). The distribution of injuries was proximal in 15 cases (26%), mid in 21 (37%) and distal in 21 (37%). Associated injuries were present in 56 patients (98%). An intraoperative diagnosis was made in 44 cases (77%). Of the patients 50 (88%) required complex repairs or an adjunct procedure, including a double pigtail stent in 33 (58%), ureteroureterostomy in 20 (35%), ureteroneocystostomy with a psoas hitch in 10 (18%), external diversion in 9 (16%), suprapubic cystostomy in 8 (14%), nephrostomy in 2 (3.5%), nephrectomy in 2 (3.5%) and ligation in 2 (3.5%). Injury grade was I to V in 5 (8%), 8 (13%), 13 (22.8%), 18 (31.6%) and 13 (22.8%) cases, respectively. Overall 51 patients (89%) survived. No deaths were related to ureteral injury. Renal salvage was achieved in 49 of the 51 surviving patients (96%). Ureteral injuries are uncommon. The complexity of repair and number of associated injuries increase with AAST-OIS injury grade. Mortality increases with AAST-OIS injury grade but it is not related to the ureteral injury. Excellent results can be achieved with complex techniques of primary repair, leading to renal salvage.