A safe and simple ultrasonic contact carotid echoarteriographic B-scanning method is described. The potential use of ultrasonic B-scanning for detection of extracranial occlusive disease before a stroke, and for longterm evaluation of atherosclerosis and its treatment, is suggested by comparing the results of the ultrasonic echoarteriogram with its analogue, the roentgenographic arteriogram, in patients with kinked common carotid artery, internal carotid artery occlusion and stenosis, normal vertebral artery, and in determining patency of internal carotid artery previously subjected to vascular surgery. Experimental dog and postmortem ultrasonic scanning studies and a historical review of the use of ultrasound to visualize the circulatory system are given in support of this work and to encourage other investigators into this field.