A comprehensive medical, social, psychiatric and dietary survey of persons 65 years of age and over was carried out in Kilsyth, a town in Stirlingshire. A total of 286 persons were randomly selected for the survey; of which 200 completed all sections, 34 refused medical examination and 52 refused to participate in any part of it. All but 2 of the total refusals were visited by one doctor. Women refused significantly more often than men. Fear of the discovery of disease was the important reason given for not wishing to participate. Mental abnormality was rare and physical disability was conspicuously absent among those who would not participate. Most of the refusals thought favourably of the Health Service and doctors. It would seem that the refusals did not importantly bias the medical or psychiatric findings of the main survey.