Abstract Arteriosclerotic arterial insufficiency of the peripheral blood vessels is often due to localized obstruction with a patent arterial system above and below the obstruction. The results of twenty-three bypass grafts in fifteen patients are reported. The clinical and laboratory methods of diagnosis, management, surgical technic and follow-up are described. The principles and advantages of the end-to-side bypass graft are presented. Of the twenty-three extremities treated with the bypass graft technic using the lyophilized homograft, the initial results were excellent in seventeen, improved in two and poor in four. Two patients in the last group had their grafts revised or replaced and are now in the excellent group. Our results as of now are: nineteen excellent, two improved and two poor. No patient's blood flow was impaired by the surgical procedures, although we did fail to prevent an amputation. There was one death. A longer follow-up is necessary before the ultimate fate of the grafts and the final outcome of these patients will be known. However, this study indicates that the lyophilized homograft is a suitable material for bypassing arterial obstructions. In addition, the bypass graft technic is an acceptable method for the treatment of segmental occlusion of the common iliacs, internal iliac, external iliac, common femoral and superficial femoral arteries. This technic may be employed for obstruction in the popliteal artery provided the distal arteries are patent and can maintain a good blood flow to the limb after the graft is in place. The vasographic examination, which is an integrated laboratory technic for examining the peripheral circulation, proved of value in the selection of patients for the bypass graft and for lumbar sympathectomy. Vasograms were of value also in following the progress of patients at frequent intervals without mortality, morbidity or discomfort to the patient. The vasographic examination made postoperative angiograms unnecessary.