In this study we report about the efficacy and tolerability of ceftazidime in the treatment of 10 cases of pseudomonal meningitis (nine Pseudomonas aeruginosa and one Pseudomonas cepacia). The 10 patients had a pseudomonal infection of the central nervous system (CNS) complicating neurosurgical procedures or developed on a preexisting immunodepressing condition; four patients were of pediatric age. All isolates were sensitive to ceftazidime with MICs ranging from 0.39 to 3.12 micrograms/ml. Ceftazidime was given intravenously at the dosage of 100-150 mg/kg/day. In seven cases amikacin was associated by intralumbar or intraventricular instillation. The duration of ceftazidime treatment ranged from 9 to 49 days with a mean of 22.2. Eight cases out of ten were cured bacteriologically and clinically, while the remaining two were cured after treatment with other antibiotics. Concentrations of ceftazidime in serum and in lumbar and/or ventricular cerebrospinal fluid (CSF) were obtained in four cases; the mean concentration in lumbar CSF was 12.2 micrograms/ml and in ventricular 3.3 micrograms/ml. The study demonstrated that ceftazidime is effective in the treatment of Pseudomonal meningitis.