Background: Clinicians had difficulties in making correct diagnoses of renal damage caused by various traumas. After blunt trauma, computed tomography (CT) is the preferred method of visualizing the internal organs. Objective: This study aimed to determine the relationship between multi detector computed tomography (MDCT) findings and clinical outcomes Patients and Methods: A cross section study was performed in Emergency Department, Zagazig University on 24 patients presented with blunt thoraco-abdominal trauma and hematuria. Focused assessment with sonography in trauma (FAST) and Contrast-enhanced multiphasic renal CT study were done to all cases. Results: There were statistically significant difference between CT & FAST specificity & PPV in diagnosing grade I renal injury. Moreover, the accuracy of CT in diagnosing grade I renal injury was statistically significant higher than that of FAST. There was statistically significant difference between CT & FAST specificity & PPV in diagnosing grade II renal injury. Moreover, the accuracy of CT in diagnosing grade II renal injury was statistically significantly higher than that of FAST. Sensitivity of CT was significantly higher than that of FAST in diagnosing grade III renal injury. The sensitivity, NPV & accuracy of CT in diagnosing grade V renal injury was significantly higher than that of FAST. Conclusion: The anatomic and functional information provided by contrast-enhanced multi-slice computed tomography (MSCT) is crucial for precise grading according to the American Association for the Surgery of Trauma (AAST) classification system, making it the gold standard in evaluation and therapy of renal trauma.