Background: Ventilator-Associated Pneumonia (VAP) refers to nosocomial pneumonia occurring 48 hours or more after initiation of mechanical ventilation (MV). Critically ill patients who is receiving mechanical ventilation may have an increased risk of VAP due to multiple factors as sputum retentions and atelectasis. Thus, different combinations of chest physiotherapy assist in the re-expansion of the atelectatic lung, confer short-term improvement in total lung-thorax compliance and expiratory flow rates, and reduce the incidence of ventilator-associated pneumonia. Objective: To identify the effect of multimodality chest physiotherapy interventions on prevention of ventilator associated pneumonia among mechanically ventilated patients. Settings: The study was carried out at the general ICUs at Damanhur Medical National institute which is classified to general ICU I (15bed) and the General ICU II (13bed). Subjects: A convenient sample of 60 adult mechanically ventilated patients from the starting day of invasive mechanical ventilation were included in the study. Tools: Two tools were used to collect the data of this study. The first tool was outcomes of multimodality chest physiotherapy assessment that was used to assess the effect of multimodality chest physiotherapy interventions. The second tool was VAP bundle observation checklist that was used to assess nurses' compliance with ventilator bundle practices. Results: The findings of the current study revealed that there was a statistically significant difference between the intervention and control groups regarding the occurrence of VAP (P= 0.001). Patients who were subjected to multimodality chest physiotherapy interventions had lower VAP rate. Conclusion: The present study revealed that patients who had a twice-daily multimodality chest physiotherapy interventions in the form of manual hyperinflation, endotracheal suctioning, patient positioning plus chest percussion and mechanical chest vibration device had a better effect on decreasing VAP occurrence as well as enhance patient`s clinical outcome than those who do not had. Recommendations: The nursing staff should use chest vibrating device with other chest physiotherapy techniques to reduce VAP in mechanically ventilated patients.