A survey was conducted on 1035 persons constituting a semi-random age-structured sample of the populations of three areas in the west of Scotland. The object was to attempt to estimate the needs of this population for domiciliary services. A method was developed of classifying the subjects into 12 'care groups' based on two characteristics, those of 'potential need' and 'solitude'. 'Potential need' was a measure of disability and its severity was graded according to the intervals that elapsed between necessary periods of help. 'Solitude' was a measure of the time during each day when potential sources of help were spontaneously available. 'Potential need' was found to be related linearly to age but to be independent of the other variables studied. 'Solitude' was commonest in the 75-84-year age group and varied in the three areas studied, but no relationship with any other variable was detected. An estimate was made of the domiciliary services which would be required to ensure a satisfactory standard of care for the subjects in the sample. Assuming present or slightly better levels of hospital provision and slightly lower provision of residential homes there is still a need for a very great increase in domiciliary services if satisfactory standards of community care are to be attained.