Bacterial meningitis in neonates and children. A high index of suspicion of meningitis is needed when evaluating neonates and young infants because clinical findings can be minimal and are often subtle and nonspecific. Analysis of the CSF constitutes the most effective method to document meningeal bacterial infection, although overlap with normal CSF values can occur, especially in newborns and very young infants. The introduction of highly active third-generation cephalosporins (ceftriaxone, cefotaxime) and their safety and efficacy in treating a broad array of bacterial pathogens that cause meningitis in all age groups has simplified selection of initial antibiotic therapy. In neonates, however, conventional antibiotic therapy with ampicillin and an aminoglycoside is appropriate because of its proven record of safety and efficacy, and because routine use of cephalosporins in the hospital nursery could lead to selection of resistant strains among gram-negative enteric bacilli. Despite the availability of modern intensive care management of infants and children with bacterial meningitis and the advent of potent antibiotics, case fatality rates and morbidity remain high. Because of this, recent research has focused on the complex interaction between bacteria and the host and on means to attenuate the meningeal inflammatory response. The clinical benefits demonstrated recently with the use of dexamethasone therapy in infants and children with bacterial meningitis underscore the importance of anti-inflammatory therapy to reduce audiologic and neurologic sequelae. Future studies of new methods to modulate meningeal inflammation such as the use of monoclonal antibodies directed against cytokines or of agents that interfere with leukocyte-endothelial interactions are indicated. The implication of routine H. influenzae type b immunization in young infants with the conjugated vaccines and optimal intrapartum prophylaxis against group B streptococcal disease in newborns will have an important impact on the incidence of meningitis in infants and children. 