Traumatic brain injuries (TBI) represent a high impact public health problem due to a high rate of death , long term disability and occurrence especially in young adults. Despite several promising animal studies, several parameters were proposed as biological markers and were assessed for this aim. Our study proposes the study of the early biochemical changes in association to hematological parameters for severe TBI patients prognosis. 43 patients with acute TBI were included in study based on clinical, laboratory and imagistic findings. The severity of the TBI was established by Glasgow Coma Scale GCS 3-8. In all patients were evaluated hematologic parameters (Red blood cell count - RBC, Hematocrit, blood Hemoglobin, White blood cell - WBC, Platelet count and biochemical parameters (glucose, urea, creatinine, electrolytes). Outcome was expressed as Glasgow Outcome Scale (GOS), between 1-5. Values were compared to control group -15 cases. Significant early differences in body temperature, heart rate, and systolic blood pressure were observed in TBI group versus control (p[0.05). After correlation, laboratory findings significantly associated to severe outcome - GOS = 1, 2 - (p[0.05) were plasma Na decrease and significant glucose increase. An early increase of temperature and decrease of Na may predict a severe outcome in patients with acute TBI; association with shifts in heart rate and blood pressure, imposes aggressive treatment measures.