Internal iliac artery aneurysms (IIAAs) are rare and their concealed location in the pelvis presents a diagnostic challenge. We report a case of a 79-year-old man who presented 12 years after an abdominal aortic aneurysm repair, with signs of prolapse, bleeding, hemorrhoids, and a deep vein thrombosis. His condition rapidly deteriorated, with the development of acute renal failure and obvious perianal and perineal ecchymoses, within a few days. Abdominal ultrasound and computed tomography showed a ruptured IIAA. His renal function returned to normal after surgical decompression of the aneurysm.