Duplex scanning with the use of continuous wave Doppler instrumentation was used for the evaluation of carotid disease and compared to angiography. In twenty such patients 100% accuracy for diagnosis of total occlusion by Duplex scanning with continuous wave Doppler, was obtained. The sensitivity for those patients with 50%-99% stenosis was 92% and for those patients with 20%-49% stenosis was 75%. The overall accuracy for this diagnostic test for all groups of stenosis was 85%. This compares favorably with other noninvasive vascular techniques and is felt to be an accurate and useful technique for the detection of carotid stenosis. Several advantages of this technique are pointed out.