Aim: The study was conducted to assess the fluoride concentrations in the water sources of Kothamangalam taluk, Kerala, India. Materials and methods: A total of 10 villages and two towns, belonging to Kothamangalam taluk, Kerala, India, were included in the study. Three samples of drinking water from each of the available water sources from each village/town were collected and analyzed for fluoride. The sources of water were—shallow wells, deep wells/borewells, rivers/canals, and municipal piped water supply. The fluoride level was measured by the colorimetric sodium 2-(parasulfophenylazo-)— 1,8-dihydroxy-3,6-naphthalene disulfonate (SPADNS) method. Results: Among the samples obtained from shallow wells, Kothamangalam town, Pindimana, Varapetty, and Keerampara villages showed a mean fluoride concentration of more than the permissible limit of 1.5 ppm. The bore wells samples of Kottappady, Neriamangalam, and Keerampara; water samples from rivers and canals of Pindimana and Neriamangalam villages, showed the high mean fluoride concentration. The samples were obtained from municipal piped water supply from all places with permissible concentrations. Conclusion: The study identified a few sources of water that contained fluoride in excess of the permissible limit in water sources from shallow wells, bore wells, and rivers. The piped water supply had acceptable levels of fluoride. Clinical significance: Fluorine is a micromineral required for normal growth, development, and maintenance of human health. Fluoride acts as a double-edged weapon. It plays an important role in preventive dentistry due to its cariostatic potential. Excessive intake of fluoride leads to fluorosis. Fluoride is found in all-natural water at some concentration.