Lethality and morbidity of blunt abdominal trauma are directly dependent on the immediately valid diagnostic work-up. Since blunt abdominal trauma usually occurs in the setting of multisystem injury and patients an no longer cooperative, clinical methods of diagnosis are unreliable, In regard to the imaging procedures, the practical approach has been simplified and standardized in the last few years. Initially, ultrasonography of the abdomen is performed. If the patient is hemodynamically unstable because of intra-abdominal loss of blood, this can be reliably detected by ultrasound and emergency laparotomy is indicated. If patients are hemodynamically stable, more sophisticated assesment of the abdomen can be achieved by computed tomography. The next step depends on direct or indirect signs of an intra-abdominal lesion. Angiography may be indicated in injuries to the liver, spleen, kidney, mesenteric root or caval vein. Lf lesions to the liver, biliary or pancreas are detected, ERCP may be required. Lacerations of hollow organs are identified by fine-needle aspiration of free intra-abdominal fluid. Findings on computed tomography are usually reliable enough to support a more conservative approach in the treatment of parenchymal lesions in blunt abdominal trauma. Since the facilities to perform ultrasound are provided in all emergency units and knowledge of ultrasonography is an essential part of surgical training, competitive diagnostic procedures like peritoneal lavage have completely lost their former important clinical role. Similarly, diagnostic laparoscopy is - in contrast to abdominal perforations - no longer of importance.