ObjectiveTo evaluate knowledge on oral health and associated sociodemographic factors in pregnant women.MethodsA cross-sectional study with a sample of 195 pregnant women seen at the Primary Care Unit Paraisópolis I, in São Paulo (SP), Brazil. For statistical analysis, χ2 or Fisher's exact test and multiple logistic regression were used. A significance level of 5% was used in all analyses.ResultsSchooling level equal to or greater than 8 years and having one or two children were associated with an adequate knowledge about oral health.ConclusionOral health promotion strategies during prenatal care should take into account sociodemographic aspects.