Twenty-three patients with a clinical and a radiological diagnosis of cranial sino-venous occlusion (CSO) were randomly assembled and selectively studied in a retrospective manner. Eleven instances were related to the presence of a meningioma and 12 were not. Patients in the meningioma group were older and had a better prognosis than the patients in the nonmeningioma group, but angiography was still necessary in all those with meningioma to diagnose CSO, whereas computed tomography (CT) was most helpful in permitting the diagnosis in the nonmeningioma group. The most frequent CT abnormality seen in this latter group was the "delta" or empty triangle sign (75% of scans), followed by cerebral edema (42%) and venous infarction (33%). One patient had a normal scan. The recent availability of intravenous digital subtraction angiography has helped confirm the diagnosis in a faster, safer and more reliable way. Careful interpretation of CT, especially in patients with CSO unrelated to meningioma, may result in decreased morbidity and mortality as a result of earlier diagnosis and treatment.