This report describes what the authors believe to be the first reported case of choristoma of the intracranial maxillary nerve. This 12-year-old girl presented with a 5-year history of severe isolated left-sided trigeminal neuralgia. Computerized tomography and magnetic resonance imaging revealed a mass below the anterior portion of the left cavernous sinus, enlarging the foramen rotundum. Total resection was achieved via a pterional extradural approach. Histological examination revealed a choristoma composed of smooth-muscle fibers. The histogenesis of these tumors when they develop in a nerve remains unclear. They may represent abnormal migration or proliferation of neuroectodermal tissue in or close to a peripheral nerve. Total removal of these tumors should be attempted at initial diagnosis.