The Extended Focused Assessment with Sonography for Trauma (eFAST) plays a crucial role in the emergency department (ED) by providing rapid and non-invasive diagnostic information in trauma patients. It is a diagnostic-free fluid detection technique that uses sonography to assess trauma in different anatomical windows of the chest and abdomen and has been accepted in multiple studies as the initial diagnostic tool for torso injuries in blunt abdominal trauma. By promptly identifying potentially life-threatening injuries, such as haemoperitoneum, haemothorax, and cardiac tamponade, eFAST facilitates timely intervention and improves patient outcomes in the ED. The eFAST exam is reliable, with high sensitivity and specificity, even when performed by non-radiological personnel, saving time and resources in the chaotic emergency environment. This review aims to assess the diagnostic reliability and limitations of eFAST in different trauma conditions and to outline its goals in trauma critical care and in “ABCDE” resuscitation.