Background: COVID-19 may put pregnant women at greater risk of serious conditions and poor outcomes for newborns. Aim: The study aimed to evaluate the effect of an educational intervention based on health beliefs model adoption on pregnant women's knowledge and preventive health behaviors in relation to COVID-19. Subjects & Method: A quasi-experimental design was performed on 100 pregnant women in the antenatal clinic of Zagazig University Hospital using purposive sampling. Data were collected using three tools: a structured interview questionnaire, the health beliefs model and preventive health behaviors of pregnant women in relation to COVID-19. Results: Scores of knowledge and preventive behaviors of pregnant women about COVID-19 have improved significantly after the adoption of the Health Beliefs Model. Conclusion: The study concluded that an educational intervention based on the adoption of the health beliefs model enhanced pregnant women's knowledge and preventive health behaviors in relation to COVID-19. Recommendations: The study suggests that health education interventions should specifically target pregnant women who may be at increased risk of contracting COVID-19.