Background: Ventilator associated pneumonia is a sever consequence in neonates receiving mechanical ventilation which represents 6.8-32.2% of healthcare-associated infections among neonates. The study aimed to evaluate effect of an educational program for nurses about prevention of ventilator associated pneumonia in neonatal intensive care units. Subjects and methods: Design: A quasi-experimental research design was used (one group). Setting: This study was applied in neonatal intensive care units at El-Salam hospital & Specialized obstetric hospital and Al-Hayat hospital affiliated to the universal health insurance in Port Said Governorate. Subjects: The study included all nurses working in the previous settings (60 nurses) and 40 mechanically ventilated neonates. Tools: Two tools were used; questionnaire sheet and observational checklists.  Results: The present study showed that only two fifths of the studied nursing staff had satisfactory total knowledge score pre-program and increased to one hundred percent immediately post program, while slightly decline at follow up phase. Also, improvements in total practices of the studied nurses throughout program phases occur which nearly one quarter of them had adequate total practice score pre-program phase, while majority of them had adequate total practice score in immediate post program phase and at follow up phase. Conclusion:  The training program was successful in enhancing nurses' skills and knowledge in reducing ventilator-associated pneumonia. Recommendations: Periodic in-service training programs are recommended to enhance nurses' performance to protect newborns against ventilator-associated pneumonia.