BACKGROUND: Thoracic and abdominal computed tomography scans are widely used modalities for trauma patients in emergency department (ED). However, alternative diagnostic and follow-up tools are also needed, due to limitations such as high cost and excessive radiation exposure. This study aimed to investigate the utility of repeated extended focused abdominal sonography for trauma (rE-FAST) performed by the emergency physician in patients with stable blunt thoracoabdominal trauma. METHODS: This was a prospective, single-center diagnostic accuracy study. Patients with blunt thoracoabdominal trauma admitted to the ED were included in the study. The E-FAST was performed on the patients included in the study at the 0th h, the 3rd h, and the 6th h during their follow-up. Then, the diagnostic accuracy metrics of E-FAST and rE-FAST were calculated. RESULTS: The sensitivity and specificity of E-FAST in determining thoracoabdominal pathologies were found to be 75% and 98.7%, respectively. The sensitivity and specificity for specific pathologies were 66.7% and 100% for pneumothorax, 66.7% and 98.8% for hemothorax, and 66.7% and 100% for hemoperitoneum, respectively. The sensitivity and specificity of rE-FAST in determining thoracal and/or abdominal hemorrhage in stable patients were found to be 100% and 98.7%, respectively. CONCLUSION: E-FAST successfully rules in thoracoabdominal pathologies in patients with blunt trauma, with its high specificity. However, only a rE-FAST might be sensitive enough to exclude traumatic pathologies in these stable patients.