INTRODUCTION: Listeria monocytogenes is a gram-positive bacillus which causes 
sporadic infections in immunocompromised humans, with a special propensity for 
the central nervous system, in the form of acute, subacute or chronic 
meningitis, rhombencephalitis or abscesses in the brain or spinal cord. The 
final diagnosis is established by germ culture in blood or in cerebrospinal 
fluid (CSF). Preferred treatment is ampicillin in association with 
aminoglycosides.
CASE REPORT: We report the case of a 70-year-old male patient with a history of 
arterial hypertension and chronic lymphatic leukaemia with no specific 
treatment, who suffered meningoencephalitis and brain abscesses caused by L. 
monocytogenes. Symptoms were a 48-hour history of headache and a febrile 
condition. The CSF showed lymphocytic pleocytosis with hypoglycorrhachia. 
Magnetic resonance scans of the brain revealed areas of cerebritis and multiple 
brain abscesses in the right frontal lobe. Specific treatment was established 
with ampicillin for 13 weeks, associated with gentamicin and vancomycin during 
the first few weeks, until x-rays showed the lesions to be resolved.
CONCLUSIONS: L. monocytogenes infections must be investigated in all patients 
with cellular immunosuppression who present febrile symptoms. The central 
nervous system may be the only area of the body infected. Moreover, this site 
will need studying in patients who present neurological focus data or an 
alteration in the state of consciousness and bacteraemia due to L. 
monocytogenes. Establishing suitable treatment as early as possible can improve 
the prognosis.