To investigate the prevalence and clinico-neuropathological characteristics of cerebral amyloid angiopathy (CAA) in aged Chinese and its relationship to dementia and cerebrovascular lesions, we examined 362 archived brains of elderly with immunohistochemical staining for beta-amyloid peptide and Congo red, Bodian and Luxol fast blue stains. We found that: (1) CAA appeared in 31.7% examined brains without sexual preponderance, and the incidence increased with age; (2) the frontal lobe was most frequently involved in CAA, followed by occipital and parietal lobe; (3) subcortical white matter and cerebellum dentate nucleus areas may also be affected by CAA; (4) CAA has a close relationship to Alzheimer's disease and multiple cerebrovascular lesions; (5) CAA alone may result in dementia.