A structured sample of mobile elderly patients in a rural community practice was assessed on validated rating scales for depression, dementia and disability. A total of 62% of the sample was abnormal on at least one variable. The overall prevalence of depression was 13%; the overall prevalence of dementia was either 10 or 18% depending on the criterion of Mental Test Score (MTS). Depression and dementia were related, depression being more common in females. In depressed and demented patients, MTS was age-related in those over 60 years; in depression alone, MTS was not age-related. Dementia was age-related, particularly over the age of 75. Disability increased with age and was more common in females. Disability was associated with both depression and dementia.