We have previously reported that cloperastine (CP), a centrally acting non-narcotic antitussive, improved micturition dysfunctions in rodents. Although clinical application of CP is expected, it is unknown whether oral administration of CP affects micturition reflex. In this study, we measured micturition functions in awake and anesthetized mice chronic orally administered with CP. Method Female BALB/c mice were purchased. CP 20mg/kg was orally administered once a day for 14 days and used for the following two experiments. 1) Real-time micturition activity of freely moving mice was measured for 24 hours by using a sequential urine collection and recording system developed by us. 2) The intravesical pressure of the urethane-anesthetized mice was measured by conventional single cystometry. Result 1) In the awake mice, CP significantly increased voiding frequency, total voided volume and voiding duration in the dark period and also for 24 hours compared with the control group. 2) In the anesthetized mice, mean urine flow rate was significantly decreased, and voiding duration tended to increase in CP group compared with control. These results suggest that chronic oral administration of CP, at cough suppressant dose, may affect micturition reflex in mice.