Background: Throughout the world, traumatic brain injury (TBI) is a leading cause of mortality and morbidity. It can be brought on by a variety of factors, including falls from great heights, gunfire, and traffic accidents. The number of injuries being treated in the emergency room is rising, and in severe trauma cases, the fatality rate might be as high as 50%. Objective: To improve the outcome of TBI patients by analyzing the vital signs at presentation and their role as a predictor to the outcome in patients with isolated TBI. Methods: Prospective analytical study that included 110 adult traumatic patients presented to Emergency Department in Suez Canal University Hospital with severe TBI. Results:Studying of the demographic data of both groups showed that most of cases 75 (68%) are males, while females were only 35 (32%).  The average heart rate was higher (100 beat/min) in cases with bad outcome compared to (89 beat/min) in cases with good outcome. The mean respiratory rate was higher (22 breath/min) in cases with bad outcome compared to (20 breath/min) in cases with good outcome. Both mean systolic and diastolic blood pressure were lower in cases with bad outcome than in cases with good outcome. Measured oxygen saturation was much lower (mean 91.6 %) in cases with bad outcome at presentation compared to 95.9 % in cases with good outcome. Conclusion:Tachycardia, tachypnea, hypotension and lower levels of oxygen saturation were evident in cases with bad outcome in sever TBI patients.