A study was done in 1994 to determine the effectiveness of the fluoridated dairy products that the Chilean National Program for Supplementary Feeding had been distributing to reduce the high prevalence of children's dental caries in rural areas of that country. For the study, the prevalence of caries was assessed in two rural communities of the Sixth Region of Chile. Children in the study community of Codegua had received fluoridated dairy products, while children in the control community of La Punta had received nonfluoridated dairy products. Three years after the program began in Codegua, the community showed a significant improvement in the indices of prevalence of caries. Over that time period, the prevalence of caries among children 3 to 6 years old declined between 40% and 60%. Among children 3 years old, the proportion of them without a history of caries increased by 74%, from 40.7% to 70.8%. Among 4-year-olds, that proportion rose by 71%, from 33.3% to 56.9%. Similar to results obtained elsewhere with programs to fluoridate drinking water, the outcomes in Codegua were achieved without any other steps by the National Program for Supplementary Feeding, such as motivational campaigns for mothers or educational efforts to encourage consumption of the program's food products.