Understanding the epidemiology (distribution and determinants) of urinary incontinence (UI), as well as its natural history is a very important issue. In this article, we discuss prevalence, incidence, natural history, and the variations that may be related to race and ethnicity. We focus on epidemiologic population comprising community-dwelling women who are not institutionalized. Our review clearly shows that there is a lack of advanced epidemiologic analyses. Variables that better characterize UI include frequency measure, quantity of urine loss, duration, type, and severity. These factors should be incorporated into basic study design so that more advanced and informative analyses may be conducted.