A group of 808 people randomly selected from those over 65 living at home were studied in three surveys designed to identify ‘disability’ and ‘dependence’, and their causes. Each subject was clinically examined, and an assessment made of mobility, continence, domestic care, self-care, and psychiatric state. ‘Disability’ was defined as inability to exist at home without help, and ‘dependence’ as a further degree of impairment of self-care. The prevalence of disability increased from 12 per cent at age 65–9 to over 80 per cent over the age of 85. In 48 per cent of the 227 disabled subjects a neurological disorder contributed to disability; 22 per cent had a functional psychiatric disorder, 38 per cent a cardiorespiratory diagnosis, 24 per cent joint disease, 16 per cent obesity, and 11 per cent visual impairment. Only 3 per cent were persistently incontinent. The prevalence of dependence as defined was 2 per cent under the age of 85 and 25 per cent over that age. Of the 27 dependent subjects 93 per cent had a neurological disorder (77 per cent with dementia); 33 per cent were persistently incontinent. These findings are discussed in the light of previous studies of disability in the elderly.