In ongoing studies in Europe and the United States, 10 pediatric patients with bacterial meningitis caused by Pseudomonas species were treated with ceftazidime. Pseudomonas aeruginosa was isolated from the CSF of 7 patients and other Pseudomonas species from the remaining 3. Eight of the 10 patients had received previous antimicrobial treatment which included aminoglycosides in 6, along with ticarcillin and ureidopenicillins in 3. Ceftazidime was administered 10 to 42 days in dosages ranging from 109 to 300 mg/kg/day. Seven of the 10 patients received ceftazidime only for 10 to 42 days. The other 3 patients received amikacin in 2 and gentamicin and tobramycin in the other. Seven patients were cured clinically and 3 died; 9 were cured bacteriologically and one who was presumed cured on the basis of clinical response subsequently died. Sterilization of the cerebrospinal fluid occurred at 48 hours to 12 days. Ceftazidime appears useful in treating bacterial meningitis caused by Pseudomonas species.