One of the most severe, life-threatening post-operative complications of abdominal aortic surgery is infection. Symptoms may occur weeks or years later and include back pain, fever, and lethargy.Since symptoms presented by the patient may be linked to graft or ureteral infection or may be due to obstruction or injury to the ureter, it is essential than an accurate, prompt diagnosis be made.If the patient has at some time undergone abdominal aortic surgery, computerized tomography of the retroperitoneum combined with retrograde urography can be helpful in a differential diagnosis. In one such case, diagnosis of ureteral injury accompanied by infection was made using the computerized tomography with retrograde urography.We believe that computerized tomography of the retroperitoneum should be used to help delineate causes of post-operative symptoms in patients who have undergone aortic bypass surgery.