We have reviewed 29 episodes of pneumococcal meningitis seen in a 6-year period (1983-1988) in 11 pediatric patients and 16 adults. An underlying disease or condition was present in 81.5% of cases, in 55.5% there was an anatomical defect, either congenital, acquired or traumatic in origin. Gram stain of CSF was positive in 86% of cases, and latex test was positive in the 22 CSF samples analyzed with this technique. MIC for penicillin ranges from 1 to 2 mcg/ml in 51.7% of cases. These isolates were also resistant to tetracycline (100%), trimethoprim-sulfamethoxazole (100%) and chloramphenicol (87%). All strains isolated were sensitive to vancomycin, rifampin and cefotaxime. Of all 14 episodes due to penicillin-sensitive strains, 10 cases were treated with this drug and in 4 cases, third generation cephalosporins were prescribed. All cases showed good clinical response. Of all 15 episodes due to penicillin-resistant strains, vancomycin was used first in 10 cases, cefotaxime in three, moxalactam in one and ampicillin plus chloramphenicol in another. Treatment failures (one in cefotaxime and one in moxalactam group) were solved with vancomycin. Of all 12 patients treated with vancomycin, clinical and microbiological cure was achieved in 10 cases. Two additional patients died, one with sterile CSF after 45 days of admission and one few hours after admission. Our data give support to vancomycin as a useful therapeutic option in the treatment of pneumococcal meningitis due to penicillin-resistant strains.