OBJECTIVE: To determine the predictors of traumatic head injury (TBI) severity in adult patients involved in motor vehicle collisions or accidents, and to report on the outcomes of hospital admission, in-hospital death, and return to the Ed within 72 hours of discharge. METHODS: This is an observational cohort of adult patients (≥18 years) who sustained a TBI through involvement in motor vehicle collisions (MVC). Demographic, pre-hospital and clinical data were collected from medical records of patients. RESULTS: In our cohort, patients who had loss of consciousness, alteration of consciousness, or post-traumatic amnesia were individual predictors of more severe traumatic brain injury. TBI severity was categorized by using GCS scores on emergency department arrival. Similarly, male patients, those who did not wear seat belts, and those with alcohol consumption were more likely to have severe TBI. When controlling for sex, loss of consciousness, no seat belt use, and alcohol consumption prior to injury were still statistically significant predictors of having more serious traumatic brain injury. CONCLUSION: Lack of seat belt use, alcohol consumption before injury, and loss of consciousness because of injury are significant predictors of having more severe head injury. These data support a call for action to implement more widespread injury prevention, seat belt use education and advocacy.