Objectives: To assess the level of knowledge and attitudes regarding prenatal and infant oral health in a sample of pregnant women from Coimbra, Portugal. Methods: A self-applied questionnaire was administered to randomly selected pregnant women who attended prenatal check-ups at two public health institutions in Coimbra. Collected data included sociodemographic information, oral health knowledge and practices in pregnancy, and knowledge on oral health in children. All ethical requirements were met. Statistical analysis was conducted using descriptive and inferential methods. Variables were tested for independence using a chi-square test with a 95% confidence interval. Results: A total of 120 women enrolled in the study. Although 68.9% of participants brushed their teeth twice daily, 36.4% reported not using floss, with a statistically significant association with age (p=0.004). Half of the respondents had not attended a dental appointment before pregnancy, and 59.2% believed pregnancy could be harmful to oral health. Findings showed limited knowledge of the possible consequences of gingivitis and periodontitis to the course of pregnancy and the importance of diet in oral health. Moreover, a low level of understanding was noted regarding the existence and prevention of early childhood caries. Conclusions: Oral health-related knowledge and practices of surveyed women were in general deficient. Considering pregnancy is a period of particular interest for acquiring knowledge and good oral health practices, which are decisive for both the expectant mother and the child, our results highlight an urgent need to implement prenatal oral health care programs in this study population.