Despite treatment, cerebral malaria still has a high mortality. This study describes the clinical features, immediate outcome and prognostic factors for childhood cerebral malaria in Mulago Hospital, Kampala, Uganda. One hundred children who met the WHO criteria for cerebral malaria were prospectively recruited and followed up until discharge or death. Mortality was 7% and neurological sequelae occurred in 5% of survivors. Independent predictors of mortality were respiratory distress [adjusted OR 1.2 (95% CI 1.1-1.3)], circulatory failure [adjusted OR 2.1 (95% CI 1.8-2.4)], generalised hyporeflexia [adjusted OR 1.2 (95% CI 1.1-1.3)] and parasite density > or =500,000/microl [adjusted OR 1.02 (95% CI 1.01-1.2)]. Circulatory failure could be predicted by a combination of hypothermia, cold peripheries and dehydration. Death occurred within 12 hours of admission only in children with these predictors, and the risk of death increased with the number of risk factors. Multiple convulsions at admission predicted neurological sequelae [adjusted OR 12.8, 95% CI 3.0-211, p=0.014)]. Cerebral malaria mortality is predictable. Patients with respiratory distress, circulatory failure, generalised hyporeflexia and parasite density > or =500,000/microl need urgent treatment to prevent death. In primary health units, health workers may use a combination of cold peripheries, hypothermia and dehydration to predict circulatory failure.