The literature regarding subcortical vascular dementia associated with periventricular and deep white matter alterations is reviewed. Information pertaining to neuropathological, neuropsychological, and neuroradiological studies is emphasized. Based on this review and prior neuropsychological studies associating subcortical vascular pathology with greater deficits on tests of executive dysfunction and with relatively better performance on tests of delayed recognition memory, we conclude that vascular dementia associated with periventricular and deep white matter alterations can and should be regarded as a subcortical dementing illness. Also, we support schemes suggested by Erkinjuntti et al. (2000) and Cosentino et al. (this issue) that attempt to integrate neuropsychological and neuroradiological data into a diagnostic paradigm that describes, as well as diagnoses, dementing disorders. We discuss questions and issues about vascular dementia that deserve further consideration and study.