Listeria monocytogenes (Lm) is an opportunistic pathogen that causes life-threatening infections, especially when the central nervous system (CNS) is involved. Here, we report a patient who was admitted to the hospital with headache, dizziness, right side facial numbness, and hoarseness. The individual was initially diagnosed with central nervous system idiopathic inflammatory demyelinating disease (CNS IIDD), which was then found to be CNS Lm infection (brainstem and cervical cord infection). CNS Lm infection mimicking CNS IIDD is rare but must be considered because the treatment is totally different and therapeutic error may be life-threatening.