Some cases of malignant arterial hypertension are reported as "pseudotumoral hypertensive encephalopathy" with a clinical picture of elevated intracranial pressure, sometimes associated with localizing symptoms, simulating brain tumor. Pseudotumoral hypertensive encephalopathy is relatively frequent in malignant arterial hypertension. It can also be provoked by other disturbances causing arterial hypertension (hormonal, renal, vascular, etc). Some cases of hypertensive encephalopathy are reported. The focal symptoms (Foster-Kennedy syndrome, signs of the posterior fossa, etc.) have been increasing difficulties. The importance of cerebral arteriography and pneumoencephalography is stressed in most of cases avoiding erroneous diagnosis.