The CT findings in 200 cases of increased intracranial pressure without localizing signs were reported 132 out of the 200 cases (63.1%) were CT positive, among them there were 8 cases with brain metastatic cancer, 11 cerebral cysticercosis, 14 intracranial inflammatory lesions, 18 hydrocephalus with symmetrical ventricular enlargement, 66 mass lesions in the brain and 15 others. 77 out of the 209 cases (36.9%) were CT negative, among whom the diagnosis of the 61 cases coincided with that of BIH. It seems that our BIH cases were much different from those typical cases reported abroad, and the cause would be pending further investigation. It is to be noted that the following remarks, according to our study, would be associated with the positive findings in CT examination: 1. age, 60 years; 2. course of disease, within 6 months; 3. papilloedema and/or "soft" signs; and 4. local and severe abnomalities in EEG.