The pattern of injury of the specific cell structures of the central nervous system (CNS) is different in the various types of the dementia syndrome. We challenged the hypothesis that this could be reflected in specific patterns of brain-specific proteins in the cerebrospinal fluid (CSF). The neuron-specific enolase (NSE), S-100, myelin basic protein (MBP) and lactate levels were retrospectively analyzed in the CSF of 159 patients with various types of dementia. A previous study from our department demonstrated age-related reference values for the brain-specific proteins in the CSF. The present study affirmed the strikingly high NSE and S-100 values in the CSF of patients with autopsydiagnosed Creutzfeld-Jacob disease: NSE, S-100 and MBP levels in the CSF of patients with various other types of dementia, and controls, did not differ significantly. Therefore we concluded that a single determination of CSF concentrations of these brain-specific proteins were of little value in the differential diagnosis of the dementia syndrome. In the diagnosis of normal pressure hydrocephalus increased levels of CSF lactate may be helpful.