In Merta block of Nagaur District, 54 groundwater samples were collected and analyzed to determine fluoride concentration. It was observed that 64.8% villages have fluoride concentration within the acceptable limit (i.e. 1.5 mg/l) and are safe for drinking in respect of fluoride concentration. As prescribed by Bureau of Indian Standard, 35.2% villages have fluoride concentration above the acceptable limit and habitants in these villages are under threat of fluorosis. The fluoride-contaminated area is further divided into three categories. About 27.8% villages have fluoride concentration between 1.5 and 3.0 mg/l which is less problematic to consumers. In Dhadhlas Uda and Bhensra Khurd village, fluoride concentration in groundwater is above 3.0 mg/l and below 5.0 mg/l which is problematic in respect to fluorosis. In the entire survey village, Chawadiya Kalan and Akhawas are in the highly problematic category. In these villages, fluoride concentration is above 5.0 mg/l. Due to the higher fluoride level in drinking water, several cases of dental and skeletal fluorosis have appeared at an alarming rate in the region.