A 60-year-old woman with a history of hypertension and chronic headache initially presented with irritative personality change and mild but steadily progressive dementia and oral tendency, left-sided hemiplegia, intense nuchal stiffness, and swallowing difficulty in the later stage. She died of bronchopneumonia at the age of 76. The brain showed marked loss of nerve cells with gliosis in the cerebral cortex and fibrillary gliosis in the white matter in addition to the typical pathological findings of progressive supranuclear palsy (PSP): extensive subcortical neurofibrillary tangles (NFTs) and loss of nerve cells with gliosis accentuated in the globus pallidus, Luys body and substantia nigra. In many case reports on PSP, the cerebral cortex is described as normal or within normal limits [Jellinger 1971, Steele et al. 1964], and to our knowledge, there is no reported case of severe cortical atrophy as seen in this case. The differential diagnosis of this case is also discussed.