Cerebral sarcoidosis was found at autography in a 68-year-old woman with progressive dementia. Of 35 previously reported cases of central nervous system sarcoidosis with dementia, only 1 was over 65 years old, and in only 2 was the presenting clinical syndrome that of a degenerative dementia. Other unusual features of the index case include the restriction of the initial cognitive deficit to memory loss and mild anomia, the scarcity of antemortem evidence for systemic sarcoidosis, a positive tuberculin test, a cerebrospinal fluid (CSF) protein concentration as high as 2028 mg per deciliter. sarcoidosis is a rare but potentially treatable cause of dementia. Consistently normal CSF probably excludes the diagnosis.