BACKGROUND Ureteral injuries are considered to be uncommon in cases of trauma. The possibility of damage to the ureters may not be considered in the setting of acute trauma when life-threatening injuries take clinical management priority. A case of acute ureteral injury is described in a patient with acute penetrating gunshot abdominal injury that had a delay in diagnosis, with a review of the literature. CASE REPORT A 29-year-old woman presented to our hospital with a missed ureteral injury following a self-inflicted gunshot injury to the abdomen. She underwent abdominal computed tomography (CT) imaging and a retrograde pyelogram, which showed complete transection of the left upper ureter with contrast extravasation and the formation of a large urinoma. She underwent a percutaneous nephrostomy and drainage of the urinoma. An end-to-end ureteric anastomosis with excision of the intervening injured ureter, or ureteroureterostomy, was performed three weeks following the diagnosis. CONCLUSIONS Ureteral injuries following trauma are rare, but a delay in diagnosis can be associated with clinical morbidity. A high index of clinical suspicion is important for early identification of ureteral injury in cases of acute abdominal trauma.