Two patients with intracranial glossopharyngeal neurinoma are described. In both patients, neurologic signs and findings of conventional radiologic and computed tomography examinations suggested a diagnosis of acoustic neurinoma. Magnetic resonance imaging, however, definitely indicated that the mass had actually arisen from the lower cranial nerves. This was confirmed at operation. The superb sensitivity and specificity of magnetic resonance imaging in the diagnosis of posterior fossa extraaxial mass are emphasized.