Opening lumbar cerebrospinal fluid (CSF) pressure was measured with a paediatric spinal fluid manometer in 26 of 61 Kenyan children (mean age 39 months) with cerebral malaria. In all cases pressure was above normal (mean [SD] 22·6 [7·4] cm CSF, range 10·5-36). Clinical features of our patients suggest that intracranial hypertension is important in the pathogenesis of cerebral malaria in children, especially as a cause of death. We suggest that raised intracranial pressure is secondary to increased cerebral blood volume. Lowering intracranial pressure may significantly reduce the mortality and morbidity of cerebral malaria. The potential risks and benefits of lumbar puncture should be considered carefully in patients with suspected cerebral malaria.