Dental fluorosis is a specific disturbance in tooth formation caused by excessive fluoride intake during the development of tooth. The aim of this study was to assess the severity of dental fluorosis in a private dental institution. This was a retrospective institutional study. Samples were collected from June 2019 to March 2020 from patient records who visited a private dental hospital. Data of dental fluorosis was collected. Excel tabulation was done. SPSS results were obtained. P<0.05 considered significant. In the present study, 191 patients had dental fluorosis. Among patients with dental fluorosis, percentage of mild fluorosis was 50%, percentage of moderate fluorosis was 26%, percentage of very mild fluorosis was 12% and 7% percentage of severe fluorosis was found. Further, 7% had questionable fluorosis. From the present study we can conclude that the frequency of mild dental fluorosis was more among the patients who visited our dental institution in chennai. Males had higher prevalence of dental fluorosis as compared to females and greater frequency of dental fluorosis was found in the age group of 16 to 30 years, However, the results were not statistically significant.