Computed Tomography (CT) is a new non-invasive diagnostic imaging method, which has ability to differentiate C.S.F., hematoma, and even edematous brain from normal brain tissue. Prior to the introduction of the CT, the diagnosis of the intraventricular hemorrhage in living patients was difficult and was confirmed by surgery or autopsy. Intracranial hemorrhages are visible on the CT with density higher than brain tissue in acute phase. CT is an accurate method for detecting of intraventricular hemorrhage including detection of nature, location, amount, and associated changes. CT is also useful as a sugical guidance and in the evaluation of fate of the hematomas by easily performable follow up studies. The causes of the intraventricular hemorrhages are hypertension, rupture of aneurysm, arteriovenous malformation, head trauma, brain tumor, and others. This study included evaluation of CT of 69 patients who show the high desnity in cerebral ventricular system during the period of 31 months from Feb. 1979 to Aug. 1981 in the department of radiology, college of medicine, Hanyang University. The results were as follows. 1. Age distribution of the total 69 patients was broad ranging from 1 month to 80 years. 28% of patients were in the 6th decade. The male to female ratio was 2:1. 2. The consciousness of parients at CT study: Those were conscious in 11 cases, stuporous in 41 cases and unconscious in 17 cases. 3. The causes of intraventricular hemorrhages were hypertension in 28 cases, head trauma in 12 cases, aneurysm in 4 cases, tumor in 2 cases and others in 23 cases. 4. 9 cases showed intraventricular hematomas only, other 60 cases showed associated intracranial hematomas: Those were intracerebral hematomas in 53 cases including 30 cases of basal ganlial & thalamic hematomas, subarachnoid hemorrhages in 17 cases, epidural hematomas in 3 cases, and subdural hematomas in 2 cases. 5. All cases of the intraventricular hematoms except one showed hematoma in the lateral ventricles, hematomas in the 3rd ventricle in 35 cases, and heamtomas in the 4th ventricle in 29 cases. 6. 28 out of 69 cases showed dilatation of the lateral ventricles. 7. Only 8 out of 69 cases were improved remarkably, 11 cases were slightly improved, and 48 cases were expired. The overall mortality was 70%. 8. The consciousness of the patient at the CT study and possible the associated intracerebral hematoma play an important role in mortality. The age of the patients, causes of hemorrhages, presence of ventricular dialtation, and methods of treatment did not affect the mortality.