A premature infant who died of early-onset group B streptococcal meningitis was found to have cerebritis with direct bacterial infection of the basal ganglia. Although the organism was sensitive to penicillin by in vitro testing, it was not eradicated from the cerebrospinal fluid after 48 h of antibiotic treatment. These findings illustrate that suppurative extension with cerebritis of the basal ganglia as a complication of group B streptococcal meningitis may be one of the factors responsible for treatment failure.