We determined the frequency of dementia in a cohort of 251 patients aged ⩾60 years hospitalized with acute ischemie stroke, based on examinations performed 3 months after stroke onset. Using modified DSM-III-R criteria, we found dementia in 66 patients (26.3%). Diagnostic agreement among raters was excellent (kappa = 0.96). In a control sample of 249 stroke-free subjects recruited from the community and matched by age, we found dementia in eight subjects (3.2%). Using a logistic regression model to estimate the risk of dementia associated with stroke in the combined samples, the odds ratio (OR) for stroke patients compared with control subjects was 9.4 (p p <0.001) with significant age and race effects. We conclude that ischemie stroke significantly increases the risk of dementia, with independent contributions by age, education, and race.