Since the optimum fluoride concentration in drinking water established for temperate countries has been considered not to be appropriate for tropical and subtropical climates, this study was conducted in Piracicaba, a subtropical, optimally fluoridated Brazilian community. The daily fluoride intake by 23 children (aged 20-30 months) from diet (liquids and solids) during the four seasons of the year was evaluated. Duplicate-plate samples of foods and beverages were collected for 2 days in each season of the year. The difference of fluoride intake during the 4 seasons was not statistically significant (p > 0.05). However, the adjusted data, based on the volume of the diet collected and on the assumption of a constant fluoride concentration in the drinking water, showed that fluoride intake during spring-summer was statistically higher than that observed during the fall-winter seasons (p < 0.05). The fluoride dose to which the children were submitted during the hot seasons would be 19% higher than that found during the cold ones. Although this dose difference would not to be a concern for a subtropical area, it could be relevant for a region with a genuine tropical climate. Copyright (C) 2003 S. Karger AG, Basel.375335338