Background: In order to enhance pulmonary perfusion and ventilation, avoid atelectasis, and facilitate the removal of secretions that have accumulated in the lungs, vibration as a chest physical therapy is required. Manual or mechanical vibrations have been demonstrated to alter respiratory perception. The aim of the Study: is to evaluate the effect of mechanical chest vibration during chest physiotherapy on ventilator parameters and oxygen saturation in mechanically ventilated patients. Design: an experimental research design was carried out in this study. Setting: the general ICU at Damanhour Medical Institute served as the study's site. Tools: the data for this study were gathered using the outcome of chest physical therapy assessment tool. Method: two equal groups; one for manual vibration and the other for mechanical vibration, were randomly assigned to patients who satisfied the inclusion criteria. Results: both groups' means for PaO2, SaO2, and SPO2 significantly improved. Mean values of blood pressure included diastolic and systolic blood pressures were significantly increased in both groups at various intervals. Conclusion: there was no discernible difference in the effectiveness of chest physical therapy between the experimental and control groups. As a result, when combined with traditional chest physical therapy, mechanical vibrator chest physical therapy can encourage sputum drainage. Recommendations: it is recommended to use mechanical vibration more often than manual vibration.