Some reports showed that urinary incontinence (UI) or female lower urinary tract symptoms (LUTS) affect life quality and sexual activity. In clinical practice, it is commonly found that not only the symptoms of UI but also overactive bladder (OAB) syndrome affect daily lifestyle and sexual activity, especially in women in the most active era in their social and personal life. However, there is lack of data proving the effect of OAB syndrome on sexual activity or sexual life quality in sexually active age group. This study aimed at evaluating the effect of OAB syndrome and UI on the sexual activity and on the sexual quality of life (QoL) of Korean women age from 20s to 40s. We investigated 3372 women aged between 20 and 49 y, enrolled via a multicenter internet survey. A structured questionnaire was used to collect data about their LUTS and sexual activities. The prevalence of OAB syndrome and UI in 3372 women was 12.7 and 21.0%, respectively. Mean subject age was 26.474.8 y and 79.5% of subjects were 20-29 y old. Having OAB syndrome or UI were found to be significant predictors of sexual life problems (OAB syndrome: OR ¼ 5.08, 95% CI ¼ 3.68-7.01; UI: OR ¼ 4.16, 95% CI ¼ 3.06-5.67). Sexual activity was significantly reduced in OAB syndrome and UI versus the asymptomatic group (OAB syndrome: OR ¼ 4.8, 95% CI ¼ 3.14-6.83; UI: OR ¼ 3.9, 95% CI ¼ 2. 81-5.27). This study is the first internet-based study concerning the sexual QoL in UI and OAB syndrome. In this study, OAB syndrome was found to cause a greater deterioration in the sexual QoL than UI. These results suggest that these symptoms have a significant impact upon women's personal and social lives and markedly affect the QoL.