Early recognition of blunt abdominal trauma in patients with multiple injuries and in shock is of utmost importance and calls for a rapid screening method. The reliability of diagnostic ultrasonography in detecting hemoperitoneum in patients with multiple trauma was evaluated prospectively. From 1986 to 1990, 291 patients with severe multiple injuries (ISS greater than 20, mean ISS 31.2) were included in the study. Laparotomy was performed on 117 patients (40%). Initial ultrasound (US) findings showed a sensitivity, specificity, and accuracy of 89%, 97%, and 94%, respectively, in detecting intra-abdominal injuries requiring surgical repair. The positive and negative predictive values were 94% and 95%, respectively. A standardized management of frequent repeat US studies can even improve on these numbers. In our department ultrasonography has replaced diagnostic peritoneal lavage (DPL) as the diagnostic study of first choice. Diagnostic peritoneal lavage is reserved for selected cases only.