Bilateral carotid angiograms of the neck in 100 consecutive adult patients show the bifurcation of the left common carotid artery to be located cranial to the right in 50% of the cases, while the right bifurcation was higher in 22%. The origin of the internal carotid artery was at the dorsal or dorsolateral aspect of the common carotid artery in 82% on the right side and in 94% on the left, while a dorsomedial or medial origin was found in 18% on the right side and in 6% on the left.