Out of 216 patients with Buerger's disease, 14 showed the involvement of the iliac artery in addition to the occlusive lesion in the leg arteries. It occurred within 2 to 8 years after the onset of symptom. The obliterative lesion of the iliac artery might owe its cause to a direct proximal progression of thromboangitis obliterans of the femoral artery or to a skip progression of the disease. The skip lesion of the iliac artery might be due to an ascending progress of the thromboangiitic lesion in the branch arteries of the iliac artery. The indication for arterial reconstruction in the case with the involvement of the iliac artery depends on run-off in the deep femoral artery. Out of the 14 cases, 2 underwent thromboendarterectomy with autogenous vein patch grafting of the external iliac artery and 6 underwent bypass grafting, but their long-term follow-up result was poor.