An analysis of falls experienced by a stratified population sample of 553 subjects, 65 years and over, was performed. It is estimated that one third of people 65 years and over experience one or more falls in a year. To analyse the association of physical and social variables with falls, the falls were divided into pattern falls and occasional falls. Pattern falls were those which, on history and examination, were assessed as arising from only minimal external upset and primarily from a disorder of balance or postural stability in the subject. Occasional falls were those which had arisen under circumstances which would be liable to cause a fit person to fall. Bivariate analysis showed those having pattern falls tended to have more functional disability, to have increased impairment of mobility, to use more aids to mobility, to be more depressed, to have lower mental test scores and to need more professional support. Women experiencing pattern falls also tended to be older and have poorer vision, while men had lower systolic blood pressure. Discriminant analysis showed that the principal effective 'predictors' of pattern falls in women were functional disability, the need for support services and informal help and the use of walking aids. In men they were functional disability and the need for support services and informal help.