Background: The clinical internship area is the best place to build nursing student knowledge. It is crucial for nursing students' education to have the chance to translate theory into practice. Evidence-based practice is an efficient strategy to improve the quality of obstetric and maternity care. Aim: To investigate the effect of the Evidence-Based Practice Program on Internship Students' Performance at the Maternity Nursing Departments. Setting: This study was conducted in the maternity departments and delivery rooms in the following hospitals, Benha University Hospital, Ministry of Health Hospital, and Benha Teaching Hospital Qaliubiya Governorate, Egypt. Study Design: A quasi-experimental (one group pre-test post-test) design. Sample size:  156 internship student nurses. Sample type: Convenience sample. Tools: Structured interviewing questionnaire; an observational checklist; the standard instrument used to assess barriers that prevent internship student nurses from achieving their competent clinical training and satisfaction tool. Results:  A statistically significant improvement between the performance of the internship students towards the first, second and third stages of childbirth as well as the care of newborns and mothers after birth before and after the implementation of the program. Also, the participants were satisfied with the evidence-based program in the delivery and maternity departments. It was observed from the breast study that a positive correlation between internship students' performance in the maternity and delivery room at pre-, immediate and eight weeks post-intervention.  Moreover, there is a strong positive relationship between the performance of the internship students in the delivery and maternity departments after implementing the program, their satisfaction with the program, and the barriers they encountered in the training place. Conclusion: The program achieved its desired results as Internship nurses' students ‘clinical performance at different stages of labor in the delivery room and maternity departments will be improved after the implementation of the evidence-based practical program. Recommendations: The Evidence-Based program to improve the internship students' clinical performance should be accessible and persistently provided to the internship student nurses in all health settings to avoid erroneous, harmful, and ineffective clinical practices as recommended by WHO.