We report the case of a 69-year-old male with large mastoid cyst on the right side accompanying cerebellar abscess. The mastoid cyst was surgically removed and the cerebellar abscess was treated palliatively with a systemic ingestion of antibiotics. Microscopical findings showed cholesterin granuloma in the cyst wall. In a review of the mastoid cyst cases reported in the Japanese literature, our case was rare because of the accompanying cerebellar abscess.
