In vestibular nerves of patients without any inner ear disease and from patients who suffered from Menière's disease, the number, diameter, and density of nerve fibres were determined in the whole nerve as well as in the different parts (pars superior and pars inferior). As regards normal values, the number of fibres in the whole nerve ranged between 17 097 and 23 088 (age group: 40-54 years). In nerves from Menière patients the number of nerve fibres was diminished: in cases of 5-7 years of duration by about 13-37%; in cases of 15-21 years of duration, by about 73%. The persisting nerve fibres showed an increase in the number of thinner fibres, but occasionally also some very thick ones with giant myelin sheaths could be observed. The number and density of nerve fibres were appreciably diminished in the nervus ampullaris anterior, posterior, and nervus saccularis. The degenerative changes in Menière's disease were more pronounced in the phylogenetically younger pars inferior with progression in the later stages of the disease.