This is a comparative study of the prevalence of dementia among elderly Chinese and Malay persons living in the community in Singapore. The subjects, aged 65 years and over, were all living in public housing estates. Two hundred elderly Chinese and 149 elderly Malay persons were interviewed. They were first screened for any cognitive deficit with the Elderly Cognitive Assessment Questionnaire (ECAQ). All those who scored 5 or fewer points on the ECAQ were then assessed with the Geriatric Mental State schedule. The results showed an overall dementia prevalence of 4.0% among the Malay elderly and 2.5% among the Chinese elderly. The rate of dementia of the Alzheimer's type was 1.8% for Chinese women and 1.5% for Malay women; for multi-infarct dementia the rate for Malay women was 4.4% and for Chinese women 0.9%. For Chinese and Malay men, the prevalence of Alzheimer's disease and multi-infarct dementia was quite similar (1.1% and 1.2%).