Based on the national Canadian Study of Health and Aging, the objective of this study was to determine the importance of socio-demographic and medical factors, cognitive and functional status as predictors of the development of urinary incontinence, and to estimate five-year incidence by sex and age group. Participants from the Canadian Study of Health and Aging who underwent a clinical examination in 1992 and were continent for urine at the time were followed up and their continence status was again determined in 1997. Multivariate logistic regression models with daily incontinence and daily or less than daily incontinence as the outcomes were developed separately for male (n = 306) and female (n = 520) survivors. Predictor variables were introduced in the following chunks: socio-demographic factors; cognitive status; functional status, diabetes and stroke. Five-year cumulative incidence of daily and less than daily incontinence by sex and age group was also estimated. Results indicated that the incidence of urinary incontinence was higher in women than in men, and increased by age in both men and women. Especially among men, those in institutions were much more likely to develop urinary incontinence than those in the community. Incontinence increased dramatically with severity of dementia, less so with physical immobility. Diabetes mellitus was related to the development incontinence in men but not in women, prior stroke was related to development of incontinence in both sexes. It is concluded that urinary incontinence is common in older persons, and enquiries about its presence should be part of routine medical and nursing assessment of older persons. Those who develop incontinence commonly have dementia and are physically impaired. The extent of assessment and management should be carefully tailored to each individual patient.