The variations of the common carotid artery, as well as of the external and internal carotid arteries, are described. During anatomic dissection on adult cadavers, we investigated the variability of appearance of 40 carotid arterial systems. Special consideration was given to the topographic relations such as the level of the bifurcation of the common carotid artery, the relationship between the external and internal carotid arteries, and the origin of the great collateral branches. Special attention was paid to the origin of the superior thyroid artery. In this article the practical importance of these variations is stressed.