The 20th century has been a major change in the age structure in most countries of the western world. Due to improved medical care the consequent decrease in mortality rates has resulted in and increase in the population in general, and in the aged in particular. The recent unprecedented interest in the health and welfare of the elderly at home is due in part to the realization that the medical and social care of elderly unfit people will continue to make ever-increasing demands on our resources of money, time and professional skill. The present work reports on a survey (1969-1971) and its follow-up three years later (1972-1974) of 300 elderly people aged sixty-five years and over, living in their own homes. It was intended that this investigation would complement and supplement information from previous studies; that this survey would provide details of the psychiatric tests and that the follow-up survey would indicate which characteristics of the subjects at first survey were associated with mortality within a three year period. Six general practices were chosen at random from two adjacent postal areas in Glasgow which were in socio-economic contrast to each other. From the lists maitained by the Executive Council, Glasgow of names and addresses of elderly National Health Service patients, a stratified random sample was drawn at three monthly intervals until 300 subjects had co-operated in the survey. Medical, psychiatric and social histories were taken during semi-structured interviews conducted by the author in the subjects own homes and complete physical examinations and assessments of nutritional intake status were made in the course of the parent survey by survey colleagues. The author's psychistric assessment of each of the 300 subjects was made in the consideration of all available data. This data was manually analysed. The semi-structured interview technique was used in the collection of data in the follow-up survey. The data from this part of the study was analysed by the assistance of a computer. The results suggested that there a high prevalence rate of conspicuous psychiatric illness in the elderly, with an increase in the prevalence of these diseases with increasing age. Those subjects mildly affected by organic brain syndrome were able to cope with their affairs whereas those moderately affected were in various stages of dependency. Severe intellectual impairment was rarely encountered since the accompanying deterioration in behavior is less tolerated by a household and more easily recognized by medical practitioners. Normative data are given for the performance scores on the psychometric tests of the Coloured Progressive Matrices (Raven 1965), the Mill Hill Vocabulary (Shprt Version) (Raven 1958) and a simple Memory and Information test. These data are displayed in quinquennial are groups. It was found that self-report inventories such as the Maudsley Personality Inventory require some adaptation in the wording for the elderly in order to avoid ambiguity in interpretation. Those subjects currently married at the time of interview provided information with regard to their attitudes to marriage, their sleeping arrangements and frequenciyes of coition. It was found at the follow-up that 194 subjects were available for re-interview at home and of these 1:1 (93%) were re-visited by the suthor. No difference in the proportion of those subjects surviving and those subjects not surviving after three years was found when allowing for age, sex, marital status, social class, the presence of inadequacies in dietary intake of calories acid, vitamin C, vitamin D, vitamin B12 and folate deficiency, but significant differences were found in the proportion of those subjects not surviving after three years when the following characteristics were considered: smoking habits, limitation of mobility, the presence of physical disability, arteriosclerotic, nervous systemic or psychiatric disease, and low sores on the short term and calculation items on the Memory and Information test. The common factor in these significant characteristics appears to be arteriosclerotic in origin. Family doctors are known to be aware of about 50 per cent of the psychiatric disorders in their elderly patients and very few of the milder cases receive any form of treatment or support, which means that elderly patients tend to be sent for specialist care only late in their illness with requests for in-patient care rather than curative treatment. This survey supports those findings. The fact that the health of the elderly person concerns not only the immediate circle of relations and close acquaintances but also the wider community has important consequences for our medical and social services. Lines of enquiry such as follow-up studies may provide some guidance in delineating the conditions under which the slow, subtle change from normality to abnormality takes place.