Objective - Pseudomonas aeruginosa meningitis is a rare clinical condition. Most of the cases are nosocomial infections. We wanted to assess the usefulness of ciprofloxacin and fosfomycin, both reaching therapeutic levels in the inflamed CSF: Material and methods - We used an experimental model in the rabbit. The P. aeruginosa strain (ATCC 25853) had a MIC 16 mg/L for fosfomycin and 0.5 mg/L for ciprofloxacin. Fosfomycin (200 mg/kg) and ciprofloxacin (25 mg/kg) were infused combined and alone. The bacterial count was assessed at TO (18 hours after the cisternal injection of the strain) and at TO + 8 hours. Results - In vivo, ciprofloxacin was bacteriostatic, and osfomycin was bactericidal, as was the combination of both agents: the bacterial count (log10 cfu/mL) down from 5.39 +/- 0.9 to 2.95 +/- 0.77 with fosfomycin, and from 6.06 +/- 1.26 to 3.16 +/- 0.83 with the combination. (C) 2000 Editions scientifiques et medicales Elsevier SAS.