The deep temporal fascia is a dense uniform aponeurotic layer covering the temporal muscle.1 There is agreement that the deep temporal fascia is a single layer attached along the length of the superotemporal line, where it blends with the periosteum14,15 and splits into the superficial and deep lamina above the level of the zygomatic arch.4,7,8,10,11,14,16- 20 However, it is controversial where the deep temporal fascia splits and where and if its layers abut the zygomatic arch or continue as the masseteric fascia over the zygomatic arch. Yaşargil et al21 demonstrated that the deep temporal fascia is divided into 2 layers at the orbital level. According to them, the superficial layer and the deep layer of the fascia that are attached to the lateral and medial borders of the zygomatic arch are separated by an intermediate fat layer. Stuzin et al4 subsequently showed that the deep temporal fascia splits into 2 layers below the supero-orbital margin. They documented that the superficial layer of the deep temporal fascia is attached to the superior margin of the zygomatic arch, overlies the periosteum of the zygomatic arch, and blends with the parotideomasseterica fascia. Salas et al9 argued that the deep layer of the deep temporal fascia is attached to the posterosuperior margin of the zygomatic arch, continues along the deep surface of the zygomatic arch, and blends with the “posteromasseteric fascia.” Ramirez et al19 found that the deep layer and the superficial layer of the deep temporal fascia fuse at 1 cm above the zygomatic arch and are attached to the superficial surface of the zygomatic arch, blending with the attachment to the fascia of the masseter muscle. Ammirati et al20 reported that 2 layers of this fascia are attached to the anterior portion of the zygomatic arch and continue with the parotideomasseterica fascia below the zygomatic arch. Campiglio and Candiani7 noted that the temporal muscle fascia split into 2 sheets at 5 cm above the zygomatic arch, with the superficial sheet abutting the anterior surface of the zygomatic arch and the deep sheet abutting the posterior surface of the zygomatic arch. These 2 fascial layers were fused in the anterior and posterior thirds of the zygomatic arch but were separated by a fat pad in the middle. Similarly, Hwang and Kim22 demonstrated that the superficial layer and the deep layer of the deep temporal fascia fused and abutted the superior margin of the zygomatic arch in 18 dissections (56%) and abutted the superolateral surface in 14 dissections (44%). Coscarella et al8 and Beheiry and Abdel-Hamid10 reported that the fascia of the temporal muscle split into 2 layers at 1 to 2 cm above the zygomatic arch or over the lower half of the temporal muscle, and the superficial fascia attached to the lateral side of the zygomatic arch. The deep fascia abutted the medial side of the zygomatic arch. In contrast, Accioli de Vasconcellos et al11 found that the deep temporal fascia was independent of the zygomatic arch (like the temporoparietal fascia) and continued caudally as the masseter muscle fascia. Our results are in agreement with the observations of all of these studies that the deep temporal fascia splits into the superficial layer and the deep layer. However, our findings demonstrate that the point where the fascia splits differs at the anterior, middle, and posterior portions of the zygomatic arch because of the fat pad between the layers of the fascia. We also show that the layers of the deep temporal fascia do not fuse above the zygomatic arch, but the 2 layers could be seen as a single layer if a cross-section was obtained near the lateral orbital rim. In most of our specimens, the superficial layer continues as the parotideomasseterica fascia, and the deep layer abuts the posterosuperior edge of the zygomatic arch. However, the superficial layer and the deep layer of the deep temporal fascia continued together across the zygomatic arch as the parotideomasseterica fascia in 27% of specimens (9 of 33 sides of 11 specimens).