Arteriosclerotic aneurysms of the abdominal aorta constitute a common clinical entity. Rarely are they associated with retroperitoneal fibrosis and ureteral obstruction requiring ureterolysis. Fifteen such cases have been reported, with resection successful in 5 of 7. A sixteenth case is presented complicated by the presence of a persistent left cardinal vein. It is the third aneurysm resected with such an anomaly, and to our knowledge the first to be associated with retroperitoneal fibrosis and ureteral obstruction. Ureterolysis with resection of the aneurysm was performed. The difficulties presented by these pathologic entities, as well as the anomalous venous pattern, are reviewed. Complete preoperative evaluation, including intravenous pyelogram, retrograde pyelography, aortography, and venacavography, for the definition of anatomic relationships and planning of the surgical approach is stressed.