The common representation of the auriculotemporal nerve is either that of a single posterior branch of the mandibular nerve or of two roots that envelope the middle meningeal artery. Our observation in the anatomy of the auriculotemporal nerve on 32 dissections ( 16 cadaveric heads) of the infratemporal fossa included: one specimen with four roots (3.1%), three specimens with three roots (9.4%), 12 specimens with two roots (37.5%), and 16 specimens with one root (50%). Furthermore, a connecting nerve branch was observed between auriculotemporal and inferior alveolar nerves in four specimens, and in another auriculotemporal nerve case, between the upper and lower roots. In the cadaver of a 70-year-old male, a four-rooted auriculotemporal nerve variation was found. These four branches lay to the posterior, combined at the posterosuperior of the maxillary and Superficial temporal arteries and formed a ganglion-like knot. From this knot, four branches stemmed and ran to the temporomandibular joint, external acoustic meatus, zygoma, and parotid gland. The knot was larger and thicker than expected; thus, it was removed and stained with haematoxylin-eosin (H&E) and S 100 for histological Studies. This structure was not a true ganglion but a structure formed by fusion of nerve fibers. (C) 2004 Wiley-Liss, Inc.