Introduction of conjugate vaccines against Haemophilus influenzae type b, Streptococcus pneumoniae, and Neisseria meningitidis has led to a substantial reduction in cases of acute bacterial meningitis in countries with high routine childhood immunization coverage. The majority of children hospitalized with meningitis in high-income countries have viral or aseptic meningitis and do not require antibiotic treatment. Cerebrospinal fluid analysis is irreplaceable in appropriately diagnosing and treating bacterial meningitis and avoiding unnecessary antibiotics and prolonged hospitalizations in children with viral meningitis. New diagnostic tests have improved detection of bacterial and viral pathogens in cerebrospinal fluid, underscoring the importance of promptly performing lumbar puncture when meningitis is suspected. This article provides an overview of acute bacterial and viral meningitis in children, focusing on the changing epidemiology, the advantages and limitations of conventional and newer diagnostic methods, and considerations for clinical practice.