Objective: The objective was to find the prevalence of dental fluorosis among school children residing in Kanpur city, Uttar Pradesh India. Materials and Methods: A total of 1343 school children, residing in the city since childhood and consuming the groundwater, in the age group of 7-17 years was selected from various schools. Schools were selected from all four directions of the city. Children were categorized in five age groups and were examined for dental fluorosis. Dean′s criteria for assessment of dental fluorosis were used, and observations were recorded on a study specific performa. Results: Among the 1343 children examined, 243 (18%) were found to be having dental fluorosis, among which number of males (131) was more than females (112). Among the different grades of fluorosis observed, mild dental fluorosis was observed in most of the cases (158). It was observed that the southern part of the city had a maximum number of cases of dental fluorosis. Conclusion: It was evident from the results that the city had a good number of cases of dental fluorosis and that the groundwater in certain areas had more than normal quantity of fluoride. Since this study was the first attempt in this area, more studies can be undertaken to substantiate our findings.