The long-term outcome and admission features predictive of outcome were determined for 61 patients with group B streptococcal meningitis treated between 1974 and 1979. Infection was rapidly fatal in 13 patients (21%). Among the 48 survivors, 38 (79%) 3 years of age or older were available for comprehensive evaluation. Excluding five who had died before age 3 years, the mean age at evaluation was 6.0 years (range 3.3 to 9.0 years). Among survivors, 11 (29%) had severe neurologic sequelae, eight (21%) had mild to moderate deficits, and 19 (50%) were functioning normally. Analysis of predictive features revealed a significant risk of death or severe impairment among infants who at hospital admission were comatose or semicomatose, had decreased perfusion, total peripheral WBC less than 5,000/mm3, absolute neutrophil count less than 1000/mm3, and CSF protein greater than 300 mg/dl (P less than or equal to 0.05). These data indicate that, although mortality from group B streptococcal meningitis has declined, approximately half of the survivors of acute infection have some degree of morbidity when evaluated at ages permitting the detection of language delay and borderline or mild mental retardation.