Intra-Arterial Digital Subtraction Angiography (IADSA) was performed in 128 patients during 13-month period. We experienced the same advantages of IADSA over conventional film-screen angiography: (1) significant reduction in contrast material dose : 1/3 of the dose of conventional angiography, (2) reduced film cost : 18% of the cost of conventional technique, (3) decreased need for selective catherization, (4) shortened examination time, and (5) more ready detection of contrast material.