INTRODUCTION: It has been suggested that fluoride in drinking water may increase the risk of osteosarcoma in children and adolescents, although the evidence is inconclusive. We investigated the association between community water fluoridation (CWF) and osteosarcoma in childhood and adolescence in the continental U.S. METHODS: We used the cumulative osteosarcoma incidence rate data from the CDC Wonder database for 1999-2006, categorized by age group, sex and states. States were categorized as low (?30%) or high (?85%) according to the percentage of the population receiving CWF between 1992 and 2006. Confidence intervals for the incidence rates were calculated using the Gamma distribution and the incidence rates were compared between groups using Poisson regression models. RESULTS: We found no sex-specific statistical differences in the national incidence rates in the younger groups (5-9, 10-14), although 15-19 males were at higher risk to osteosarcoma than females in the same age group (p<0.001). Sex and age group specific incidence rates were similar in both CWF state categories. The higher incidence rates among 15-19 year old males vs females was not associated with the state fluoridation status. We also compared sex and age specific osteosarcoma incidence rates cumulated from 1973 to 2007 from the SEER 9 Cancer Registries for single age groups from 5 to 19. There were no statistical differences between sexes for 5-14 year old children although incidence rates for single age groups for 15-19 year old males were significantly higher than for females. CONCLUSION: Our ecological analysis suggests that the water fluoridation status in the continental U.S. has no influence on osteosarcoma incidence rates during childhood and adolescence.