We treated a 9-year-old boy suffering from underdevelopment of the length as well as circumference of the left lower extremity due to idiopathic arterial calcification of the left ilio-femoral artery. There was no deposition of calcium on the other arteries and tissues of the body. He had undergone aorto-internal iliac bypass graft with resection of the calcific iliac and superficial femoral arteries in the National Fukuoka Central Hospital when he was 4 years old, but the graft became occluded. He was admitted to the University of the Ryukyus Hospital. The common femoral artery was completely occluded with severe deposition of calcium on the wall and with gritty contents. The profunda femoris artery and the proximal part of the superficial femoral artery were also completely occluded with organized thrombi. Re-establishment of blood flow to the ischemic left lower extremity was performed with an ilio-femoral cross-over synthetic bypass and femoro-popliteal saphenous vein bypass graft, in situ. The patient has been well with adequate pulses of the pedal and posterior tibial artery 8 months after surgery.