The Gasser’s ganglion is the largest of the 12 cranial nerves. It has a sensory function by innervating the face and a motor function by innervating the muscles of mastication. It is important to note that it also participates in the innervation of the dura mater and supports multiple connections and anastomoses, such as the facial nerve, the glossopharyngeal nerve, the vagus nerve, and the C2 and C3 segments. This ganglion is connected to the pterygopalatine fossa through the foramen rotundum, which is crossed by the maxillary nerve. In the field of neural therapy and anesthesia, the techniques described so far reach the vicinity of the ganglion through the foramen ovale. Especially the anesthetic technique requires management in operating rooms, the use of a fluoroscope, and presents some risks due to the structures that are in relation to the foramen ovale. In an investigation carried out in cadavers using methylene blue, it was found that the Gasser’s ganglion can be infiltrated by diffusion through the pterygopalatine fossa by means of the foramen rotundum. The authors of this chapter have verified the appearance of hypoesthesia or anesthesia in the three branches of the trigeminal nerve after infiltration, as well as relaxation of the mastication muscles. The application of this technique is generally safe, in the experience of more than 500 applications by the authors.