Brain trauma is an imperative concern for preventable mortality and disability throughout the lifespan. Aim: The study aimed to evaluate the effect of the semi-fowler position during suctioning on oxygenation among patients with brain trauma. Subjects and Method: Design: a quasi-experimental design was used in this study. Setting: This study was implemented at the Suez-Canal University Hospitals, specifically at the critical care units.  Subjects:  a purposive sample that included 100 mechanically ventilated patients on pressure-controlled mode, distributed randomly by half into control and study groups. Tools: The first tool is called the patient's physiologic parameters questionnaire, which consists of two parts (patient's profile and oxygenation as indicated by ABGs values). The second tool is called the hemodynamic (cardiorespiratory) parameters recording sheet to assess and evaluate PR, RR, BP, MAP, and CVP. Results showed that (42%, 46%) of the participants were diagnosed with epidural hemorrhage among the control and study groups, respectively, with a high statistically significant improvement in PH, PaO_2, SaO2, and PaCO₂ values, in addition to the hemodynamic (cardiorespiratory) parameters among the study group after suctioning at the semi-fowler position. Conclusion study concluded that total oxygenation value was increased significantly in the study group with (86.70± 8.49) compared to (80.70±6.30) in the control group after endotracheal suctioning at 30 degrees head of bed elevation (HOBE) with P = 0.001. Recommendations: Further research is required to examine the long-term effects of HOBE on oxygenation and different hemodynamic functions in relation to the critical care unit's stays.