We compared CT and MRI findings among 78 Alzheimer's disease (AD), 66 vascular dementia (VaD), and 41 stroke without dementia (SWD) African-American patients to identify possible neuroimaging indicators of dementia. The patients with AD and VaD were generally older and less educated than those with SWD. VaD and SWD patients had a higher frequency of cardiovascular disease risk factors than those with AD. In multivariate analysis, the CT data showed that the presence of white matter lesions, nonlacunar infarcts, and left subcortical infarcts were predictors of VaD when compared with AD, whereas atrophy of the third ventricle and equal distribution of white matter lesions distinguished VaD from SWD. On MRI, atrophy of the temporal sulci, temporal horns, and the third ventricle, and right hemisphere infarcts, distinguished AD from VaD, while atrophy of the third ventricle differentiated VaD from SWD. These data suggest that atrophy, especially at the level of the third ventricle, presence of infarcts, and white matter lesions may be useful predictors of dementia subtype. Furthermore, the qualitative CT and MRI findings among our African-American patients were similar to those reported in other dementia studies.