An iliac vein aneurysm is a rare vascular anomaly, scarcely reported in the vascular literature. We present the case of a 72-year-old man with a history of a remote heart transplant complicated by severe tricuspid regurgitation and traumatic abdominal injury, who was incidentally found to have a 10-cm right common iliac vein aneurysm. Because of the size and risk of rupture, we elected to treat him with surgical iliac vein aneurysmorrhaphy. His iliac venous diameter and flow continued to be stable at subsequent follow-up.