24-year-old black female presenting with progressive paralysis of the left lower limb. The clinical examination and investigations describe an extensive retroperitoneal mass. An exploratory laparotomy reveals a ruptured saccular infrarenal aortic aneurysm, a narrowing of the distal aorta and a complete obstruction of the left common iliac artery. The aneurysm was resected, an aortoiliac bypass and femorofemoral crossover bypass were performed, with success. The clinical presentation of this ruptured abdominal aneurysm is unusual. Its etiology is discussed: the findings are suggestive of Takayasu's disease.