Background: Dengue fever is one of the leading causes of hospitalization. Educating the patient is the responsibility of the nurse, which is one of the most important aspects of patient post-cardiac surgery. Aim: To determine the effect of educational guidelines on pregnant women's knowledge, practice, and anxiety regarding dengue fever. Subjects and method: Design: A quasi-experimental research design was used to achieve this study. Setting: The study was applied in antenatal outpatient clinics at Sohag University Hospital. Subjects: A purposive sample of 100 pregnant women involved in the study from the previously selected settings. Four tools were used: Tool (I) a structured interview questionnaire, Tool (II) pregnant women's knowledge regarding dengue fever, Tool (III) pregnant women's practice regarding dengue fever, (pre/post), and Tool (IV) a State-Trait Anxiety Inventory scale. Results: A statistically significant difference was detected between pregnant women's level of knowledge and practice regarding dengue fever after educational guidelines intervention. Also, the study demonstrated that there was a highly statistically significant difference in anxiety scores at (P= <0.001) among the studied pregnant women after educational guidelines intervention. Conclusion: Educational guidelines intervention has a positive effect on enhancing pregnant women's knowledge and practice and decreasing their anxiety level regarding dengue fever. Recommendations: Educational instruction intervention regarding dengue fever is recommended in various maternity healthcare settings. Educational booklets should be provided about dengue fever for pregnant women and taught using the booklet and illustrated pamphlets for each one to improve their information and reduce their anxiety levels in addition to replication of the current study with a larger sample of patients undergoing cardiac surgery in different settings is required for generalizing the results.