Ceftazidime was prospectively evaluated in the treatment of bacterial meningitis in 19 pediatric patients. Haemophilus influenzae type b (HIB) was the etiologic agent in 17 patients, and Streptococcus pneumonia and Neisseria meningitidis were the etiologic agents in one patient each. Ceftazidime was administered intravenously in a dosage of 150 mg/kg/day divided into eight hourly doses for a mean of 15 days (range, 14 to 22 days) for H. influenzae type b meningitis. The clinical and microbiologic response was appropriate in all cases. The mean ceftazidime CSF concentration was 6.7 micrograms/ml at approximately 2 hours following iv infusions. This concentration was 16- to greater than 100-fold the minimal bactericidal concentration determined for the isolated pathogens. These preliminary observations support ceftazidime as a candidate cephalosporin for the treatment of bacterial meningitis caused by H. influenzae. Additional study is required to further define its role in meningitis caused by S. pneumoniae and N. meningitidis.