Neurofibromatosis type 1 (NF-1) is associated with fatal vascular complications. A 40-year-old woman with NF-1 who had previously undergone left iliac artery ligation and femorofemoral bypass grafting for internal iliac artery (IIA) aneurysm rupture was transported to our hospital for the treatment of a newly developed IIA aneurysm. Although endovascular therapy was difficult owing to the previous surgery, we successfully performed embolization of the aneurysm and its feeding vessels via direct percutaneous puncture under ultrasound guidance. Aneurysm enhancement had completely disappeared at 2 months postoperatively. We have reported a novel approach of direct percutaneous puncture for IIA aneurysm embolization in a patient with NF-1.