In 58 cases with central pontine myelinolysis (CPM) and/or extrapontine myelinolysis, systematic examination of the central nervous system was performed. The demyelinating disease occurred in three subtypes: (1) CPM, in which the lesion was confined to the pons, (2) CPM combined with extrapontine myelinolysis and (3) exclusively extrapontine myelinolysis. Type (1) was found in 27 cases, (2) in 18 cases and (3) in 13 cases. Cerebellum and lateral geniculate body were the most frequently affected extrapontine regions. One case with an extreme extension of the lesions is described in detail. Extrapontine lesions seem to be more frequent and widespread than has been hitherto reported in the literature.