No bacterial disease has undergone a more dramatic change in epidemiology during the past decade than acute bacterial meningitis. This review describes the changing epidemiology and considers some important recent observations that contribute to our understanding of the pathogenesis and pathophysiology of meningitis. The major focus is on the mechanisms of neuronal injury and the pathophysiologic concepts responsible for death and neurologic sequelae. In recent years, experimental studies have amplified our understanding of the substantial body of evidence that now implicates cytokines and chemokines, proteolytic enzymes, and oxidants in the inflammatory cascade leading to tissue destruction in bacterial meningitis. The molecular mechanisms responsible for oxidant-induced neuronal injury in meningitis are explored in some depth. Genetic targeting and/or pharmacologic blockade of the implicated pathways may be a future strategy for therapeutic adjunctive measures to improve outcome and may hold substantial promise, in concert with antimicrobial agents, in humans with acute bacterial meningitis.