Glioneuronal tumor with neuropil-like islands (GTNI) is a rare and novel mixed neuronal-glial tumor that typically affects the supratentorial cerebral hemispheres of adult patients. It is extremely rare for GTNIs to be in the spine of pediatric and adolescent patients, and there have been no reports of infratentorial GTNIs. We report a case of an elderly patient with an anaplastic, infratentorial GTNI that occurred in the cerebellum, including describing MRI features of our case.