We report a 4-year-old boy with fulminating meningitis caused by Haemophilus influenzae (Hib). He suddenly developed fever, vomiting and then somnolence. As bacterial meningitis was suspected, treatment with antibiotics was started at 12 hours after the onset. However, there was a rapid progression of severe brain edema and brain hernia, leading to clinical brain death. His clinical course and neuroradiological findings mimicked those in patients with acute encephalopathy, with cytokine profiles in cerebrospinal fluid demonstrating a marked increase of inflammatory cytokines. From a review of the literature, fulminating Hib meningitis may be classified into two disease types: DIC plus multiple organ failure and acute brain swelling types. The present case belongs to the latter type, in which cytokine storm seems to play an important pathogenic role.