The pterygoid plexus is a complex of veins located in the infratemporal fossa of the skull with comprehensive connections to surrounding veins and anatomical structures. Bordering the pterygoid plexus are the medial and lateral pterygoid muscles along with the temporalis muscle, while the maxillary artery is surrounded by the plexus. As a result, the tributaries of the venous plexus parallel the branches of the maxillary artery. A clinically significant attribute of the pterygoid plexus is its communication with the cavernous sinus, the inferior ophthalmic vein, and the facial vein. Due to these communications, one must be aware of the potential to spread infection through the venous system into the cranial cavity. In addition, one must understand the anatomy of the infratemporal fossa and the pterygoid plexus when administering a block injection of the posterior superior alveolar nerve due to the risk of penetration and potential hematoma formation.