Labyrinthitis ossificans is a pathology consisting of calcification of the membranous labyrinth resulting in profound sensory deafness. It is usually due to an acute inflammatory process that progresses to ossification of the labyrinth. The clinical manifestations are irreversible hearing loss, dizziness and vomiting. It is diagnosed by computed tomography (CT) and magnetic resonance imaging (MRI). It is important to make the correct diagnosis before cochlear implantation, as ossification of the labyrinth can hinder or prevent the implantation of electrodes.