Fluoride is often found in elevated concentrations in volcanic areas due to the release of magmatic fluorine as hydrogen fluorine through volcanic degassing. The exposure to high levels of fluoride can affect the processes of bone formation and resorption causing skeletal fluorosis, a pathology that can easily be mistaken for other skeletal diseases. In this study, we aimed to determine if fluoride concentration in the femoral bone of wild populations of the house mouse (Mus musculus) is a good biomarker of exposure to active volcanic environments naturally enriched in fluoride, allowing their use in biomonitoring programs. The fluoride concentration of the whole femoral bone of 9 mice from Furnas (5 males and 4 females) and 33 mice from Rabo de Peixe (16 males and 17 females) was measured by the potentiometric method with a fluoride ion selective electrode. Fluoride in bones was significantly higher in the mice from Furnas when compared with the mice from Rabo de Peixe (616.5?±?129.3??g?F/g vs. 253.8?±?10.5??g?F/g). Accumulation rates were also significantly higher in the mice collected in Furnas when compared with Rabo de Peixe individuals (3.84?±?0.52??g?F/day vs. 1.22?±?0.06??g?F/day). The results demonstrate a significant association between exposure to fluoride in the active volcanic environment and fluoride content in bone, revealing that bone fluoride concentration is a suitable biomarker of chronic environmental exposure to fluoride.