Multidrug-resistant Acinetobacter baumannii is an emergent nosocomial pathogen. A 61-year-old woman developed meningitis caused by MDRAB 27 days after receiving a surgical intervention for invasive meningioma. The patient failed to respond to high doses of meropenem and sulbactam treatment and the organism persisted in the cerebrospinal fluids for two months. The regimen was changed to intravenous and intrathecal colistin for 28 days and the patient responded well. Administration of colistin both intravenously and intrathecally could be a suitable option as a salvage therapy for meningitis due to multidrug-resistant A. baumannii.