Acinetobacter species is a non-fermentative aerobic gram-negative coccobacillus that is an important pathogen found in nosocomial infections. Recently, multi-drug resistant Acinetobacter baumannii (MDR-AB) infections have been increasing and pose a serious problem. Most such infections present as bacteremia, pneumonia, or a wound infection; however, CNS infections are very rare. We herein present a case of ventriculitis caused by MDR-AB in a 37-year old man after a neurosurgical intervention. The patient was successfully treated with intrathecal colistimethate.