The significance of cerebral white matter lesions in vascular dementia was mentioned, based on the findings of 50 autopsied cases at Yokuhukai Geriatric Hospital. Neuropathology of vascular dementia is classified to 5 types, i.e. 1) lacunar type, 2) cortical type, 3) cortico-white matter type, 4) white matter type, and 5) Binswanger type. Our findings on 50 patients revealed no lacunar type, cortical type in 8 cases, cortico-white matter type in 19, white matter type in 9, and Binswanger type in 14. The fact that 42 patients out of 50 showed some lesions involving the cerebral white matter suggested the important role of the white matter lesions in the pathogenesis of dementia of vascular type. Our cases also indicated that Binswanger type be commonly observed, although dementia of this type has been thought to be very rare since Binswanger (1894) and Alzheimer (1902) had reported similar patients. The patients with cerebral white matter lesions develop more marked dementia, especially of frontal and parieto-occipital type, than ones with cortical lesions, but the characteristics of symptoms of white matter and Binswanger type remain to be fully clarified.