Surgical interventions on the infratemporal fossa require an accurate knowledge of the surgical anatomy. Thirty-four adult human skulls were examined and measurements made of the distance between the zygomatic arch and the root of the lateral pterygoid plate. The distance between the central part of the lateral and medial pterygoid plates was also measured. The first measurement represents the distance of the foramen ovale from the zygoma; the average being 38.2 mm. The average distance between the pterygoid plates is 9.6 mm. Addition of these two measurements represents the distance of the lateral wall of the nasopharynx from the zygoma and the average is 47.8 mm. Together with the knowledge of the arrangement of the muscle layers and the nerves and vessels in this region, this information has proved useful in the surgery of the area.