More than 600,000 people in the three districts in Rarh Bengal, namely Purulia, Bankura and Birbhum live in fluoride endemic area where dental, skeletal and non-skeletal fluorosis is wide spread. Rarh Bengal is in an extended part of Chotanagpur Plateau in Eastern India. Fluoride content in 727 water samples of drinking water and petrography of 34 rock chip samples from these districts have been studied to understand fluoride in the drinking water. About 1753 households (in 410 villages) were surveyed using stratified random and quota sampling techniques to assess the number of people affected by fluorosis. Fluoride risk analysis was performed by applying the standard fluoride hazard index and fluoride vulnerability index. Results showed that granite gneiss and pegmatite are responsible for release of fluoride ions into the soils and groundwater. About 118 villages in 14 blocks of Purulia, 15 villages in 7 blocks in Bankura and 9 villages in 5 blocks in Birbhum are found to be affected by severe fluorosis.