Haemophilus influenzae is an uncommon cause of bacterial meningitis in adults. This report describes a prospective evaluation of 16 episodes of community-acquired H. influenzae meningitis in a nationwide study on bacterial meningitis. Predisposing conditions were present in eight (50%) of the 16 episodes; the most common predisposing conditions were otitis or sinusitis (five episodes; 31%) and remote neurosurgery or head trauma (three episodes; 19%). One (6%) episode was fatal and hearing loss occurred in four (25%) episodes. It was concluded that H. influenzae meningitis in adults is a disease with a rather benign clinical course and a relatively good prognosis compared with pneumococcal meningitis.