The author demonstrates on three selected observations clinical, radiological and neuropathological symptoms of Binswanger's disease. Its cause are changes of the long medullary arterioles which supply the white matter of the brain, most frequently in conjunction with hypertension. The basis of changes is ischaemic periventricular leucoencephalopathy. The disease is, contrary to recent ideas, very frequent and is formed by a spectrum of subclinical changes to deep dementia associated with neurological symptoms. Binswanger's disease is found isolated and combined with Alzheimer's disease or with multiinfarc dementia and is together with this unit the most frequent cause of vascular dementia in adult and old age.