Thirty children with bacterial meningitis were randomized to receive either ampicillin and chloramphenicol in standard doses or cefotaxime (50 mg/kg/dose every 6 h) for 10 to 14 days. Eighteen patients received ampicillin and chloramphenicol and 12 patients received cefotaxime. Cerebrospinal fluid isolated included: Haemophilus influenzae (20), Streptococcus pneumoniae (4), Neisseria meningitidis (3), Group B streptococcus (2), and Salmonella enteritidis (1). Five of the H. influenzae isolates were ampicillin resistant but no isolates were resistant to cefotaxime. The minimum inhibitory concentrations of cefotaxime for 30 isolates ranged from 0.0004 to 0.06 mg/l, while the minimum bactericidal concentrations ranged from 0.007 to 0.12 mg/l. The cerebrospinal fluid bactericidal titres for the cefotaxime-treated group ranged from 1:64 to 1:1024. On the second day of therapy the mean cefotaxime serum concentrations were 56.9 +/- 28.7 mg/l at 1 h and 3.66 +/- 5.65 mg/l at 6 h after administration of the drug whilst mean desacetyl-cefotaxime serum concentrations were 12.31 +/- 7.56 mg/l at one hour and 7.96 +/- 8.26 mg/l at 6 h respectively. Cerebrospinal fluid concentrations of cefotaxime and desacetylcefotaxime measured one hour after drug administration were 3.72 +/- 5.57 mg/l and 4.35 +/- 7.12 mg/l, respectively. No adverse drug reactions were noted in either treatment group. Cefotaxime proved to be both as safe and as efficacious as standard therapy for the treatment of bacterial meningitis in children.