Treatment of arterial hypertension in severe hypertensive encephalopathy does not always result in clinical improvement in the patient's central nervous system. In order to elucidate further the status of the brain, the authors have measured intracranial pressure (ICP) and arterial pressure in three cases of severe hypertensive encephalopathy. ICP was elevated in two of the three cases with peak values ranging from 32-70 mm Hg. In these 2 patients, therapy to lower ICP, including hyperventilation, steroids, barbiturates, and furosemide was begun early in the course. Cerebral perfusion pressure (CPP), defined as the difference between mean arterial pressure and ICP, was kept over 50 mm Hg to maintain adequate cerebral blood flow (CBF). These 2 patients survived. In the third case, measures to control ICP were instituted late in the course and the patient died of brain herniation. Intracranial hypertension is a complication of hypertensive encephalopathy and may contribute to cerebral injury. In cases of severe hypertensive encephalopathy, both ICP and arterial pressure should be monitored continuously. Judicious therapy aimed at lowering both ICP and arterial pressure, while maintaining an adequate CPP, should be employed.