20% of patients with multiple injuries have abdominal injuries. Patients with massive symptoms and signs indicating abdominal injury should receive high priority in the treatment of the multiple injury patient, second only to injuries to airways and thorax. The unstable critically ill patient must undergo laparotomy without further investigation. In a patient in extremis, however, left emergency thoracotomy and clamping of the descending aorta should be performed prior to the laparotomy. Extensive abdominal haemorrhage should be treated first with a tamponade to control the bleeding, after which the patient should receive further transfusions and treatment to correct acidosis. It is then possible to proceed with further necessary surgical repair. In many patients with multiple injuries, however, the problem is to diagnose the abdominal injury. Peritoneal lavage is a sensitive but unspecific method of diagnosis, and the discovery of blood in the lavage fluid is not an absolute indication for laparotomy. Sometimes injuries to parenchymatous organs may be treated without operation. This necessitates good clinical judgment, available adequate diagnostic imaging techniques and repeated examinations by an experienced surgeon.