We describe the successful use of endovascular occlusion of the iliocaval confluence to prevent excessive bleeding during open repair of an iliocaval arteriovenous fistula due to a ruptured abdominal aortoiliac aneurysm. A 70-year-old man was admitted with chest pain, hemodynamic instability, acute pulmonary edema, and bilateral leg swelling. Computed tomography angiography (CTA) showed a ruptured AAIA with a large primary iliocaval fistula. Aortobifemoral bypass with a Dacron bifurcated prosthetic graft was performed with catheter balloon occlusion of the iliocaval confluence to prevent massive bleeding. Follow-up CTA showed no complications. Iliocaval fistula is a rare complication of AAIA that requires emergent surgery. Endovascular occlusion of iliac or inferior cava vein can control bleeding.