This study aimed to determine the prevalence of dental fluorosis in a sample of 3,313 schoolchildren (ages 12 and 15) in a health district in Salvador, Bahia, Brazil. A cross-sectional study was developed, and data were collected by seven examiners (kappa = 0.69) according to WHO criteria (the Dean index). Additional information such as participation in programs, access to a dentist, place of residence from 0-5 years of age, sex, and ethnicity were obtained through a questionnaire. A descriptive analysis was performed for the municipality as a whole and for each district. According to the results, 31.4% of the 12-year-olds and 27.6% of the 15-year-olds presented fluorosis, predominantly of the "very mild" type. Differences were found between the districts (p<0.05). The districts of Pau da Lima and Brotas had the highest percentages of healthy individuals at 12 years of age (81.8% and 81.6%). At 15 years, Subúrbio Ferroviário, Pau da Lima, and Cajazeiras were the districts with the lowest prevalence rates (13.0%, 14.6%, and 13.5%). The district of Liberdade had the highest prevalence (72.4% and 57.3%) at 12 and 15 years, respectively, attributed to differences in calibration. Differences were found between the health districts, thus emphasizing the need for health surveillance.