OBJECTIVES: In the present study, we estimated the costs of management of overactive bladder (OAB) symptoms in Japan and investigated the cost reduction effect of improved hospital visit rate of symptomatic persons. METHODS: To estimate the costs of OAB symptoms in Japan, we collected a variety of epidemiologic and economic literature on OAB or urinary incontinence. Three types of costs were considered: OAB treatment costs (medication, diagnosis and hospital visits), direct costs (OAB-related costs including treatment for urinary tract infections, skin infections, and fractures and incontinence care costs including pads, diapers, and cleaning) and indirect costs (work loss due to work absence and decreased productivity). The analysis included community-dwelling Japanese males and females aged 40 years or older. Potential cost saving was estimated on the assumption that the hospital visit rate would increase from the current 22.7% to 35% and 50%, respectively. RESULTS: The numbers of OAB symptomatic persons and OAB patients were estimated at 8.6 million and 2.0 million, respectively. The annual costs for OAB were estimated at ¥956.2 billion, and ¥112,000 per OAB symptomatic person. The breakdown of annual cost was: ¥180.9 billion (19%) for OAB treatment (including medication of 159.1 billion yen), 62 billion yen (6%) for OAB-related costs, 28.7 billion yen (3%) for incontinence care and ¥684.6 billion (72%) for work loss, which accounted for the largest part. The potential annual cost saving was estimated as ¥92.7 billion and 205.8 billion for the assumed hospital visit rate of 35% and 50%, respectively, and ¥88,000 per newly visiting OAB patient. CONCLUSIONS: It was revealed that economic loss due to OAB symptoms is enormous in Japan. It might be possible to reduce the cost for OAB by appropriate treatment for OAB symptomatic persons.