This study identified factors that are associated with dental fluorosis among school adolescents in an endemic area using a control design. Data were collected using a directed self-administered questionnaire. Dental fluorosis was confirmed by a dentist. Out of the 472 students who participated in the study, 398 had dental fluorosis and the remaining 74 were free of dental fluorosis. A logistic regression analysis revealed children born in Wonji compared to those born elsewhere [Adjusted OR (95% CI): 5.12 (2.68, 9.75)]; males compared to female [Adjusted OR (95% CI): 2.76 (1.52, 5.00)]; and those who obtained their regular drinking water from pipe distribution compared to those who obtained water from other sources [Adjusted OR (95% CI): 3.5 (1.24, 10.02] were more likely to have dental fluorosis. Students in the age group 13-14 year compared to those in 11-12 year were less likely to have dental fluorosis [Adjusted OR (95% CI): 0.43 (0.25, 0.76)]. The findings indicate that the risk of dental fluorosis is still much higher for the population in Wonji and recommend strengthening appropriate intervention systems at household and community levels.