BackgroundOral health is one of the most important factors affecting the general health of the community and families; in this regard, parents, especially mothers, can play an effective role in the oral and dental health of children. This study aimed to evaluate the knowledge of pregnant women on children oral and dental health in the first pregnancy.MethodsThis cross-sectional and descriptive-analytical study was conducted on 200 pregnant women in the second and third trimesters of pregnancy referred to Obstetrics and Gynecology clinics and private offices in Isfahan-Iran from. To assess the knowledge of mothers about oral and dental health, a researcher-made questionnaire including 24 questions was used which was evaluated and verified in terms of validity and reliability. Collected data was analyzed by SPSS software version 22 using Pearson correlation coefficient and Spearman tests. The significance level was considered to be less than 0.05.ResultsThe results of this study showed that the knowledge of mothers on the oral health of the child was 8.66 ± 4.53, so that their knowledge was moderate in 82 (41%) and 109 (54.5%) in poor level And 9 (4.5%) were high. In addition, the relationship between mother’s age (r = 0.288), maternal education (r = 0.497) and family’s economic status (r = 0.182) with the mother’s knowledge of oral health were significant (P <0.05).ConclusionThe level of knowledge of pregnant mothers on their child’s oral and dental health was low, so it seems necessary to hold workshops and provide useful information before or during pregnancy.