A case of neurinoma arising from the accessory nerve is reported. The tumor was small and located entirely within the jugular foramen; the patient sought treatment for a jugular foramen syndrome. The lesion was visualized only on magnetic resonance imaging, and surgery confirmed that it originated from a cranial root of the accessory nerve. There have been no previous reports of a small, accessory neurinoma that is confined entirely to the jugular foramen, appearing with a typical jugular foramen syndrome.