Problems of surgical indication and technique for the treatment of chronic occlusive arterial diseases remain unresolved, especially in the cases which show poor angiogram run-off. To establish the surgical technique of omental transplantation, anatomical findings of the omental vessels were studied. The anatomical findings of the omentum were classified into two types. Type I (single layer) and Type II (double layer), and subdivided into seven subtypes according to the number of omental arterial branches. Omental transplantation was performed in our clinic in 19 cases (20 limbs) and surgical results were satisfactory. The examination of microscopic findings of the implanted omentum and the ischemic muscle of the implanted limb by consecutive serial sections suggested that the vessels of the omentum might invade the ischemic muscular tissue and supply blood to the muscle. Omental transplantation should be considered one of the most useful surgical techniques in cases with poor angiogram run-off.