Listeria monocytogenes is a gram-positive bacillus that exhibits predilection to 
infect the central nervous system in immunocompromised individuals; the most 
common manifestations are meningitis and rhombencephalitis. Listerial brain 
abscesses are rare. We report here two brain abscess cases caused by L. 
monocytogenes in patients receiving immunosuppressive agents. The first patient 
presented with left hemiparesis mimicking stroke and the second patient 
presented with neurological symptoms without fever, which was indistinguishable 
from brain tumor. In both cases, magnetic resonance spectroscopy (MRS) was 
performed to differentiate infectious processes from other causes. Diagnosis was 
made with a positive blood culture in both cases. Listerial DNA was detected in 
the pus aspirated from the abscess in the first case. Both patients were 
successfully treated with intravenous ampicillin followed by oral amoxicillin. 
MRS was useful in differentiating infectious processes from non-infectious 
causes.