Many cases of age-related cognitive dementia are caused by cerebrovascular lesions, and various vascular syndromes can lead to cognitive impairment and dementia. Repeated cortical infarcts due to embolic disease of the heart or major cerebral vessels can cause progressive deterioration towards dementia and incapacitation. In classic multi-infarct dementia, cognitive deterioration is stepwise rather than smoothly progressive. While diagnostic technologies have vastly improved and added to general knowledge of the pathology of cerebrovascular disease, MRI, PET, and transcranial Doppler scans have demonstrated that significant white matter change is possible without clinically recognized TIA or completed stroke. In addition, patients may have initial complaints that are not serious enough to produce changes on mental status examination. Many patients have mixed dementia, exhibiting aspects of both degenerative brain disease and clinical evidence of strokes or significant changes on MRI scan. The overlap between vascular and degenerative disease is significant, yet the exact interaction of the pathophysiology of the vascular lesions and the degenerative changes is not known. The treatment of vascular or mixed dementia involves control of the risk factors for continued vascular events and treatment with the cholinesterase inhibitors.