The aim of this study was to assess the prevalence of urinary incontinence and other lower urinary tract symptoms among an aged population and follow this prevalence longitudinally. A random sample of 70-years-olds participated and the survivors have been reinvestigated longitudinally, between 70 and 97 years of age. The prevalence of urinary incontinence was 17%, among men and 48% among women 70 years of age. No change in the total prevalence of urinary incontinence or stress incontinence was seen among those that were investigated at the age of 70, 75, 79, 81, 85, 88, 90, 92, 95 and 97. There was some increase in the prevalence of urge incontinence among men and women and some increase in the prevalence of weak stream among men. Urinary catheters were uncommon in this investigation, even among the oldest, and those with long-term catheter use had a high risk of dying. In this study, urinary incontinence was common among men and women 70 years of age. Those who participated in all examinations up to very high age had no increase in prevalence of total urinary incontinence or stress incontinence, but there was some increase with increasing age in the prevalence of urge incontinence and weak stream. These increases were, however, smaller than those found in cross-sectional studies, perhaps due to the fact that those who attended these investigations were healthy and active and, therefore, not afflicted as much, and when they were, they tended to seek help more often. Indwelling catheter use was uncommon in this group of elderly individuals and those who had a catheter had a high mortality, probably due to the fact that only the very ill get an indwelling catheter in Sweden today. (C) 2002 Elsevier Science Ireland Ltd. All rights reserved.