Meningitis refers to inflammation of the meninges surrounding the brain. Meningitis may vary from a benign, self-limited condition to one that may cause disability or death. The most common bacterial pathogens are Streptococcus pneumoniae (pneumococcus), Haemophilus influenzae type B, Neisseria meningitidis (meningococcus), and group B beta-hemolytic streptococci (Streptococcus agalactiae). Adults and older children with meningitis may present with neck stiffness, fever, headache, and altered mentation. Lumbar puncture with cerebrospinal fluid analysis is the mainstay for diagnosis and should include opening pressure, cell count, total protein, glucose, Gram stain, culture, and polymerase chain reaction testing. Empiric, guideline-directed intravenous antibiotic therapy should be started within 1 hour of presentation and continued until a specific organism can be identified. Routine vaccination against the common bacterial pathogens meningococcus, H influenzae type B, and pneumococcus is recommended. Chemoprophylaxis is recommended for close contacts of those infected with H influenzae type B or meningococcus.