Ossification of the inner ear is the result of multifactorial pathogeneses, such as infection or malignant infiltration, and otosclerosis. Ossification of the innerear spaces is a well documented sequela of suppurative labyrinthitis. In this study of human temporal bones, sections from 14 patients (28 temporal bones)were studied. In additionto the osseous tissue within the inner ear, findings included neoplasms, otosclerosis, otitis media, trauma, and Fabry's disease. We have attempted to correlate these conditions and their influence on the formation of osseous tissue within the spaces of the inner ear. Tympanogenic infection and vascular compromise were found to play an important role in ossification. The scala tympani ofthe basal turn of the cochlea was frequently the site involved.