In developed countries the mortality from bacterial meningitis acquired outside the neonatal period is relatively low. In contrast, in developing countries it is often higher (20%-40%). In developed countries despite (and perhaps because of) the introduction of increasingly potent antimicrobials, the morbidity of bacterial meningitis has remained high. For example, up to 25% of patients with Haemophilus influenzae meningitis have some form of neurological deficit. Neisseria meningitidis is the major cause of bacterial meningitis in many areas of the world. A clone of Group A meningococcus has spread from China to cause the most recent major epidemic in Sub-Saharan Africa. Group B meningococcal infections causing sporadic meningitis are increasing in parts of Europe and South America. The mortality from meningococcal disease is greatest when there is a septicaemic component to the infection. Although antimicrobial chemotherapy is of major importance some adjuncts to therapy are beneficial. High dose corticosteroid therapy has been shown to decrease mortality in pneumococcal meningitis in an uncontrolled study and to speed recovery and decrease neurological sequelae in H. influenzae meningitis. Nevertheless to prevent infection would be of greater benefit. Prevention can be achieved by either chemoprophylaxis or immunoprophylaxis. Although safe and effective vaccines are available to prevent pneumococcal, H. influenzae (Hib) and Groups A and C meningococcal meningitis; apart from the protein conjugate Hib vaccine they are less effective in children under two years of age. There is no effective vaccine to protect against group B meningococcal meningitis.