Higher brain dysfunction generally refers to cognitive and/or behavioral changes resulting from stroke, traumatic head injury, hypoxic encephalopathy, or any other of a number of cerebrovascular events. In 2004, the Ministry of Health, Labour and Welfare of Japan released a provisional figure of the probable prevalence of higher brain dysfunction in Japan as some 300,000 individuals. The aim of this study was to provide an estimate of the number of people with higher brain dysfunction in Tokyo. All 651 hospitals in Tokyo were surveyed between January 7, 2008 and January 20, 2008 by questionnaire. Analysis of the data showed 118 incidents of brain damage which resulted in higher brain dysfunction. This roughly converts to 3,010 incidents per year in Tokyo. Taking life expectancy into consideration, we estimate the current number of higher brain dysfunction survivors to be 49,508 (male : 33,936, female : 15,572) in Tokyo. The social impact of higher brain dysfunction has recently emerged amid growing recognition that disturbances of attention, memory, and behavior overshadow the contribution of focal motor deficits to chronic dependency. Our data provide information about the number of people that may require appropriate provision in the community.