Peripheral arterial disease, because of its significant and prolonged morbidity and related mortality is a major medical and surgical problem. Contrast angiograrn remains the essential standard for the anatomic demonstration of disease. It does not, however, provide data suitable for quantification or any evaluation of the microcirculation. For these reasons, radionuclide studies are playing an increasingly important role by not only confirming the diagnosis and offering objective data on the physiologic significance of anatomic lesions, but by offering prognosis of healing and prediction of therapeutic results. In addition, radionuclide procedures offer means t.o safely and repeatedly monitor response to therapy and long term follow up. 1'he object of this study was to evaluate the clinical availability of 'Tl perfusion scan in patients with peripheral arteriai diseases. We performed 'Tl perfusion scans in patients with five Buerger s disease (10 legs), six DM gangrenes (12 legs) and classified three perfusion pattern groups. Finally we compared treatment modalities among each groups and compaired Tl-201 perfusion scan findings with angiographic findings in six patients with Buergers disease. The results were as follows: 1) Seven legs showed increased perfusion in stress image and normal or increased perfusion in resting image (type 1). Six legs showed decreased perfusion in stress image and irnproved in resting image (type II). Of total 13 legs, only 1 leg needed to amputation. 2) Three legs showed decreased perfusion in stress and resting irnage (type III), and subsequently all cases were received surgical amputation. 3) In six Buergers disease patients, there were disagreernents in two patients (2 legs) between 'Tl scan and angiography, in which angiograms were normal but 'Tl scans shawed type II perfusion patterns.