Objective: To determine the predictive value of repeated abdominal ultrasonography in patients with multiple trauma and decreased level of consciousness (LOC).Methods: This prospective cross-sectional study was conducted over a six-month period at Shahid Rajaee Trauma Hospital, Shiraz, Iran. We included hemodynamically stable blunt abdominal trauma patients with a decreased LOC (Glasgow Coma Scale ≤ 13) who were referred to the neurosurgery ICU ward. Included cases underwent 1 contrast-enhanced CT scan and two-time ultrasonographic study of the abdomen with an interval of 48 hours. The diagnostic accuracy of the ultrasonography was determined according to the CT-scan results.Results: Overall 80 patients with mean age of 37.75 ± 18.67 years were included. There were 17 (21.3%) women and 63 (78.8%) men among the patients. Compared with the CT-Scan, the first ultrasonography showed a sensitivity of 60%, specificity of 80%, PPV of 16.60%, NPV of 96.80%, and a diagnostic accuracy of 70%. The same values for the second ultrasonographic study were 80%, 79%, 20%, 98%, and 79%, respectively. In 4 (5%) patients whose first ultrasonography and CT scan results were negative, the second ultrasonography was positive for injury.Conclusion: In patients with blunt trauma to the abdomen, when the only indication of abdominal CT scan is a decreased LOC, two ultrasonographic studies can replace a CT imaging.