Since the first report by Berberich and Hirsch in 1923, conventional angiography had been playing essential roles in diagnosis and treatment in the field of Orthopedic Surgery. Angiography is still the most definitive method for evaluating arterial disease, and is also an invaluable aid in the diagnosis of certain abnormalities which characteristically alter the normal vascular pattern. But the clinical use of conventional angiography as a routine diagnostic study has been limited by the risk associated with arterial catheterization cost, and poor patient acceptance. With improvement of radionuclide angiography and development of the methods for the identification and amplification of signals from small quantities of intravascular administered iodinated contrast agent and their combination with image subtraction (so called digital subtraction angiography, DSA), we have partially substituted the DSA and Radionuclide angiography for conventional angiography in diagnosis and post-operative evaluation of orthopedic patients. We have analyzed and compared the 197 cases who had taken conventional angiography from August, 1981 to July, 1985, and 16 cases who had taken radionuclide angiography from January, 1983 to July, 1985, and 21 cases who had taken DSA from October, 1983 to July, 1985 in Department of Orthopedic Surgery, Seoul National University Hospital. The results were as follow: 1. Conventional angiography is the most reliable and most widely used method in diagnosis of peri pheral arterial disease and evaluating the distribution of peripheral circulation of patient who need arterial reconstruction. But the clinical use of the angiography has been limited by the risk of complications. 2. DSA is simple, relatively non-invasive and can be done in out-patient basis. DSA is particulary useful and can replace the conventional angiography in post-operative assessment of peripheral vascular reconstruction, in the assessment of blunt and penetrating peripheral arterial trauma, and in the evaluation of peripheral aneurysm and vascular malformation. 3. Radionuclide angiography is also simple, and has no morbidity and useful in the patients who may be allergic to the contrast medium. Radionuclide angiography is useful in the evaluation of obstruction of major artery, deep vein thrombosis, and in repeated post-operative evaluation of arterial reconstruction.