The results of 150 examinations by computed tomography in emergency situations are described (about 5% of all CT examinations). There were 80 examinations of the skull, 65 of the abdomen and five of the mediastinum. The results are shown in two tables and include the diagnosis of bleeding, infarcts and inflammatory lesions (abscesses, encephalitis, acute pancreatitis). The morphologic and densitometric findings are compared with the literature and with other imaging procedures. Computer tomography has assumed the most important place in the emergency diagnosis of the skull; as regards the abdomen, it reaches its limitations in the presence of acute vascular occlusion and diseases of the gastro-intestinal tract. In this situation other procedures (contrast studies, angiography) and endoscopy are to be preferred since these demonstrate the tubular organs longitudinally, unlike the transverse image produced by the CT scan. Acute diseases of the lungs can be demonstrated more quickly and simply by conventional radiography. CT is a non-invasive and rapid procedure, which can demonstrate haemorrhages, abscesses and exudates in the mediastinum and abdomen directly and also show their topography. The method is therefore essential for emergency diagnosis of conditions involving the trunk.