OBJECTIVE: To investigate the effect of high levels of fluoride on children's intelligence development by analyzing the literatures systematically. METHODS: The literatures on the relationship between endemic fluorosis and children's intelligence development published between 1995 and 2007 were retrieved electronically and manually. A total of 13 relevant literatures that met the inclusion criteria were included for Meta analysis. Meta analysis was performed using the Coorporative network software RevMan 4.3. RESULTS: The subjects of the 13 literatures included 2 508 children from the high fluoride group and 2 330 children from the control group. Meta analysis showed these literatures were inhomogenous (χ2=268.05, P<0.01). Therefore a random effect model was used. The average effect scale (OR=-7.14; 95%CI: -9.90, -4.37) suggested a negative correlation between high fluorosis exposure and children's intelligence development. CONCLUSIONS: Exposure to high levels of fluoride may adversely influence children's intelligence development.