Background: Postpartum period is a serious period that needs special health care for both mother and baby. The study aimed to evaluate the effect of the educational guideline program on internship nursing students' knowledge and skills regarding postnatal evidence-based-nursing-practice in the postnatal unit. Design: Quasi-experimental (pre and post-test) design. Setting: The study was conducted at the postnatal unit affiliated to the obstetric department in maternity hospital in port-Said city. Sample: A convenient sample of 84 internship students. Tools of data collection: four tools were used to collect the necessary data: (1) Interview questionnaire for students' characteristics; (2) An observational checklist; (3) Reeda scale; (4) Visual analog scale. Results: There was a highly statistically significant difference between the total score of knowledge, and practice among internship students pre and post-test (p <0.001). Conclusion: A statistical improvement in students' knowledge and practice after implementation of the educational program intervention. Recommendation: Developing continuous educational programs and workshops should be planned regularly for the internship nursing students receiving training in postnatal unit to enhance their skills regarding Evidence-Based-Nursing-Practice.