OBJECTIVES: Overactive bladder (OAB) is characterized by urinary urgency, usually accompanied with frequency and nocturia, with or without urgency urinary incontinence, in the absence of urinary tract infection (UTI) or other obvious pathology. This study was performed to investigate the prevalence of OAB and the effect of hormone therapy (HT) on the OAB prevalence in healthy Korean postmenopausal women. METHODS: The frequency, nocturia, urgency, and urgency incontinence were investigated by using questionnaire in 350 healthy postmenopausal women over 45 years old among patients who visited the Department of Obstetrics and Gynecology, Chung-Ang University Hospital, between November 2010 and February 2011. RESULTS: In our study, the prevalence of OAB was 14.3% and OAB with urgency incontinence was present in 8.0% of the investigated participants. There was no difference in OAB related to older age or the presence of HT, but signifi cant difference was found in the duration of menopause (odds ratio [OR] 3.451, 95% confidence interval [CI] 1.422-8.377, P = 0.004). Higher risks for both frequency (OR 2.921, 95% CI 1.587-5.375, P = 0.001) and nocturia (OR 2.469, 95% CI 1.069-5.702, P = 0.037) were observed in OAB subjects compared to postmenopausal women without OAB. CONCLUSION: To the best of our knowledge, this is the fi rst study investigating the prevalence of overactive bladder in Korean postmenopausal women. Older age or HT did not affect the prevalence of OAB, and HT was not effective in treating the symptoms of OAB. However, the prevalence of OAB was increased with the age, duration of menopause.