According to public health research, exposure to casinos is a risk factor for disordered gambling. Consequently, casino self-exclusion programs, which provide gamblers with the opportunity to voluntarily seek limits on their access to gambling venues, can serve as a barometer of the concentration of disordered gambling in an area. This study reports on the distribution, both temporally and geographically, of 6,599 people who applied to exclude themselves from Missouri casinos between November, 1996 and February, 2004. Analyses used Microsoft MapPoint to plot the location of casinos and self-excluders (SEs) across Missouri and its constituent counties. These regional exposure analyses showed that the Western region around Kansas City is an epicenter of disordered gambling as, to a lesser extent, is the Eastern region around St. Louis. The annual number of SE enrollments increased during the first few years of the Missouri self-exclusion program and then leveled off during the later years. These findings have important implications for public health and the development of public health interventions for disordered gamblers.