Labyrinthitis ossificans is the pathological ossification of the membranous labyrinthine spaces in response to processes which are destructive of the membranous labyrinth or the endosteum of the otic capsule. It has been primarily a histopathologic diagnosis. Complex motion tomography however, allows a detailed view of the osseous labyrinth and permits the diagnosis in the living state. Radiologic documentation of labyrinthitis ossificans is objective evidence of a process destructive of the membranous labyrinth. It supports the likelihood of an absence of cochlear and vestibular function. It alerts the surgeon to the possible obliteration of key inner ear anatomical landmarks.