Background: The aim of this population-based cross-sectional study was to determine the prevalence and risk factors of urinary incontinence (UI) in women aged 20 years or older and to assess its influence on the quality of life (QOL). Materials and Methods: The study group was comprised of 625 women determined using the stratified sampling technique according to age and residence. The data were collected through a questionnaire and the Urinary Incontinence Quality of Life Instrument. Results: The prevalence of UI was 25.8%. UI was significantly associated with body mass index ( OR 12.75, 95% CI 6.68-24.6), diabetes mellitus ( OR 3.55, 95% CI 1.44 - 8.73), neurological disorders ( OR 3.80, 95% CI 1.69 - 8.58), recurrent urinary tract infections ( OR 4.73, 95% CI 2.52 - 8.88). Impairment of QOL was related with the type of UI, frequency of UI episodes, amount of leakage and UI during sexual intercourse. Conclusion: Our study results determined that UI is common in women. The QOL of women was either mildly and moderately affected by UI. Copyright (C) 2004 S. Karger AG, Basel.