Acinetobacter baumannii is an important cause of postneurosurgical meningitis. The emergence of carbapenem-resistant strains in this setting has caused a therapeutic challenge. We investigated the clinical implications of postneurosurgical meningitis caused by carbapenem-resistant A. baumannii. In this study, we retrospectively reviewed the medical records of patients more than 16 years of age with A. baumannii meningitis that developed after a neurosurgical procedure at five university-affiliated hospitals between January 2005 and May 2011. Of 40 cases identified, 22 (55.0%) were caused by carbapenem-resistant strains. Of those evaluable 36 patients with A. baumannii meningitis, 14 (38.9%) died of meningitis. Meningitis-related mortality was significantly related to carbapenem resistance (59.1% versus 7.1%; P = 0.002). In patients with meningitis caused by carbapenem-resistant A. baumannii, colistimethate-containing regimens (4/13 versus 7/9; P = 0.040), intrathecal or intraventricular (IT/IVR) administration of antibiotics (2/13 versus 8/9; P = 0.001), and combined intravenous and IT/IVR therapy (2/13 versus 6/9; P = 0.026) were significantly associated with cure. This study shows that use of colistimethate and combined systemic and local administration of antibiotics should be considered for the treatment of meningitis caused by carbapenem-resistant A. baumannii.