BACKGROUND This community-based epidemiologic study of dementia in a rural population in India investigated the prevalence of various dementing disorders in the community, psychosocial correlates of the morbidity, and assessment of the risk factors associated with dementia. METHODS A door to door survey was conducted to identify elderly people aged 60 and above. A total of 2067 elderly persons were then screened with a vernacular adaptation of the MMSE. All those who scored 23 and below had a detailed neuropsychological evaluation by CAMDEX-Section B, and the care-givers of the people with confirmed cognitive impairment were interviewed using CAMDEX-Section H to confirm the history of deterioration or impairment in social or personal functioning. In the third phase the subjects with confirmed cognitive impairment were evaluated at home as to whether they satisfied the DSM-III-R criteria for dementia. Subcategorisation of dementia was done based on ICD-10 diagnostic criteria. Five percent of those whose screening was negative were randomly selected and evaluated during each stage. RESULTS Sixty-six cases of dementia were identified from 2067 persons aged 60 and above, a prevalence rate of 31.9 per thousand. After correction this rate was 33.9 per thousand. Fifty-eight percent of the dementia cases were diagnosed as vascular dementia and 41% satisfied the criteria for ICD-10 dementia in Alzheimer's disease. There were more women in the Alzheimer's disease group; smoking and hypertension were associated with vascular dementia while a family history of dementia was more likely in the Alzheimer's group. CONCLUSIONS Dementia is an important cause of morbidity in the geriatric population in this community, where families take responsibility for the care of relatives with dementia.