Ascending pharyngeal-vertebral anastomosis has been identified by angiography of the carotid artery in several cases. We present a case of ascending pharyngeal-vertebral anastomosis that was found incidentally in computed tomography angiography of the ascending pharyngeal artery. Images revealed that the anastomosis formed through the hypoglossal branch of the neuromeningeal trunk. The anastomosis seemed to be associated with hypoplasia of the right vertebral artery. Interventional radiologists should be aware of this dangerous anastomotic route of the APA to the VA. Discovery of hypoplasia of the major intracranial arteries before intra-arterial chemotherapy or embolization in head and neck area may avoid subsequent complications.