Objective: To estimate the prevalence of and identify factors associated with urinary incontinence in older women. Methods: A cross-sectional study involved 7949 community-dwelling women, with a mean (± standard deviation) age of 76.9 ± 5.0 years, recruited from population-based listings to participate in the Study of Osteoporotic Fractures. The prevalence and severity of urinary incontinence during the previous 12 months were assessed by questionnaire. Factors potentially associated with urinary incontinence were assessed by questionnaire, interview, and physical examination. Multivariate logistic regression analysis was used to determine the independent associations between these factors and the primary outcome of daily incontinence. Results: Forty-one percent (3285) of the women reported urinary incontinence, with 14% (1130) reporting daily incontinence. In multivariate analysis, the prevalence of daily urinary incontinence increased significantly with age (odds ratio [OR] 1.3 per 5 years, 95% confidence interval [Cl] 1.2-1.5), prior hysterectomy (OR 1.4, 95% CI 1.1-1.6), higher body mass index (OR 1.6 per 5 units, 95% Cl 1.4-1.7), history of stroke (OR 1.9, 95% CI 1.3-2.7), diabetes (OR 1.7, 95% Cl 1.2-2.4) chronic obstructive pulmonary disease (OR 1.4, 95% CI 1.1-1.9), and poor overall health (OR 1.6, 95% CI 1.3-2.1). Faster gait speed (OR 0.8 per 0.2 units, 95% Cl 0.6-1.0) was associated with decreased incontinence. Conclusion: Urinary incontinence is a common problem in older women, more common than most chronic medical conditions. Of the associated factors that are preventable or modifiable, obesity and hysterectomy may have the greatest impact on the prevalence of daily incontinence. (Obstet Gynecol 1996;87:715-21).