Late-onset progressive myelopathy, years after odontoid fracture, is considered a rarity. Undiagnosed or untreated odontoid fractures may develop into nonunion or malunion, thereby leading to secondary delayed cervical myelopathy. We present a case of a 50-year-old man with malunion of odontoid fracture. We had a good result following one-staged posterior decompression and occipito-cervical fusion.