After a summary of the embryology and anatomy of the arterial blood supply of the face, the authors present the descriptive anatomy of the facial artery and its eight most frequent branches. Variations of the origin, course and division of the artery are then described. The literature contains 3 to 5 different descriptions of the course of the artery. The authors considered 4 of these descriptions to be relevant: I (angular), II (nasal), III (superior labial), IV (hypoplastic). Seventeen different branches have been described, many of which are inconstant. The superficial and deep anastomotic network is described, with emphasis on the subdermal network and that of the transverse facial artery. The various vascular regions of the face, first described by Mitz and Whetzel, are described. Based on these observations, and on Lasjaunias'theory of the triple hemodynamic balance, the authors propose a functional analysis of the arterial blood supply of the face. According to this analysis, the anatomic variations observed are determined by regional hemodynamic balances. These observations influence the design and creation of certain local facial flaps, such as the submental, nasolabial and buccinator flap. They may also influence present concepts concerning the hemodynamics of arteriovenous malformations of the face.