We constructed an expandable endovascular metallic stent in the same way as Gianturco did. Experiments were made to test the ability of these stents to be used in the vessels. A total of 20 stents were passed through a 8.5 French teflon sheath into the normal abdominal aorta, IVC, and iliac artery of four adult dogs for 4 weeks to 12 weeks ; 5 stents (10mm in diameter fully expanded and 20 mm in length) in the abdominal aorta, 7 stents 912 mm/20 mm) in the IVC, and 5 stents (8 mm/20 mm) in the iliac artery. All but two stents showed no migration, and one complete occlusion occurred in right iliac artery of a dog. Histologically, stent wires were covered by neo-intimal proliferation. The side branches of the main vessels remained patent, even with stent wires across their orifices. These metallic stents may be used as an endovascular graft material in the nonsurgical treatment of several forms of vascular disease.