Purpose: To assess the risk factors involved for active white enamel lesion in public schoolchildren, aged 7 to 12 years, in Natal, Brazil, using a case-control study. Materials and Methods: A total of 273 cases of active white enamel lesion and 325 controls (lesion-free) were matched by age, gender and school. The independent variables were: age; gender; visible plaque index (VPI); gingival bleeding index (GBI); decayed, missing and filled surfaces (DMFS); decayed, extracted or filled surfaces (dmfs); DMFS-dmfs; and the number of carious surfaces. Results: There was no statistical significance for age (p = 0.57), gender (p = 0.428) and dmfs (p = 0.06). Univariate analysis revealed an increased risk of developing active white enamel lesions in individuals with high VPI (OR = 15.5, CI 95% 10.35-23.2), GBI (OR = 2.86, CI 95% 2.05-3.99), DMFS (OR = 18.91, CI 95% 12.51-28.59), DMFS-dmfs (OR 10.22, CI 95% 7.01-14.91) and number of carious surfaces (OR = 5.47, CI 95% 3.85-7.78). Logistic regression analysis identified that GBI (OR = 2.14, CI 95% 1.41-3.25) and DMFS (OR = 17.3, CI 95% 11.39-26.27) were independent risk factors for active white lesions. Conclusions: The results reaffirm the importance of mechanically controlling biofilm to prevent caries development in its initial stage (white lesion). Palabras clave: case-control study, dental caries, enamel demineralisation