Fluorosis is the most widespread side-effect of fluoride use and appears as discrete white spots on the enamel up to severe enamel dysplasia. There are different techniques for scoring fluorosis in epidemiological surveys. In the literature there is no uniform way of selection of teeth and data processing. Fluorosis risk is determined by environmental factors such as water and food fluoride content as well as individual factors such as use (or misuse) of fluoride supplements and fluoridated oral hygiene products. In a group of Flemish schoolchildren, fluorosis prevalence is low and mainly related to use of fluoride supplements and toothpaste in childhood.