The research project was initiated to conduct a cost/benefit analysis for those communities whose fluoride levels exceed two times the optimum and to determine the economic impact of defluoridating community drinking water. The initial data used in this study were from a project conducted by the University of Texas at San Antonio for the Environmental Protection Agency's Health Effect Research Laboratory. This earlier project was used to select representative cases of fluorosis from each community with water fluoride levels from optimum to 4.0 ppm. The clinical findings of each case were presented to a panel of clinical practitioners for diagnosis of the extent of cosmetic deformity and dental dysfunctional effects present in the dentition as a result of excessive fluoride. Cost estimates were made for the remedial care proposed for each subject by each panel member. Using these data an evaluation was made of the beneficial effects of optimum water fluoride levels (savings from caries reduction) against the adverse costs of excessive fluoride.