Introduction: In order to prevent unnecessary deaths and severe morbidity in these patients, it is crucial to evaluate the hemodynamic status of polytrauma patients as well as to screen for continued bleeding and evaluate the effectiveness of resuscitation. Aim of this study: To assess inferior vena cava (IVC) /aortic index importance in assessment of intravascular volume status and in prediction of early blood transfusion in trauma patients. Patients and methods: This study was conducted as a prospective cohort study. The major blunt trauma patients were divided into two groups. Patients group had signs of shock such as decreased blood pressure<90/60 mmHg or a more than 30% decrease from the baseline systolic pressure, heart rate >100 b/m, cold clammy skin, capillary refill >2 sec Control group: had normal blood pressure (≥90/60 mmHg) and normal heart rate, no other signs of shock. Results: There were 31 patients (51.7%) required blood transfusion after 24-hour. The mean 24-hour blood transfusion was 1556.3 ± 1081.9. IVC/aortic index 0 at presentation in case group, mean ± SD was 0.60 ± 0.12, while in control group mean ± SD was 0.98 ± 0.08 (p-value < 0.001). IVC/aortic index 1 in case group, mean ± SD was 0.70 ± 0.12, while in control group mean ± SD was 0.94 ± 0.09 (p-value < 0.001). Conclusion: The IVC/aorta diameter index can be used as a parameter for detecting volume status and early blood transfusion in polytrauma patients.