Overactive bladder (OAB) is a common medical condition. A number of health-related quality of life (HRQOL) measurements for OAB have been developed during recent years, including the linguistic validation of the traditional Chinese version of the Kings' Health Questionnaire (KHQ). However, limited studies are available for this version of KHQ. Hence, the aim of this study was to examine the reliability and discriminant validity of this traditional Chinese version within the communities of Taiwanese. A cross-sectional and case–control study was designed. On the basis of a convenience sampling, participants were recruited at a community health center in Pingtung County, Taiwan from March to July 2010. The collected data included OAB symptoms assessed by the Overactive Bladder Symptom Score (OABSS), the HRQOL assessed by the traditional Chinese version of the KHQ and demographic characteristics. Subjects with urinary urgency at least once a week and a total score of OABSS ≥ 3 were assigned to the OAB group. Participants without OAB but with matched age and gender were selected as the control group. Internal consistency reliability was assessed using Cronbach's α, and discriminant validity was examined by Student's independent t-test. A total of 173 pairs of observations were matched and analysed. The Cronbach's α value was above 0·80 for the traditional Chinese version of KHQ and all its subscales, suggesting a good internal consistency reliability for this measurement. The participants in OAB group showed poor quality of life than the controls (all p < 0·001), which display a good discriminant validity of traditional Chinese version of KHQ. Only 39·9% (n = 69) participants with OAB had discussed their symptoms with a doctor during the past year. As the HRQOL could be improved by medical help, health care providers should educate the public about OAB and encourage patients to seek medical attention.