IRIS is described as a paradoxical deterioration of clinical status upon initiation of combined anti-retroviral therapy (cART) in patients with HIV infection. Immune reconstitution inflammatory syndrome (CNS-IRIS) involving the central nervous system is rarely reported. We describe the case of 57-year-old man who developed a fatal case of CNS- IRIS. A rapid deterioration of neurological status was associated with progression of patchy T2-weighted hyperintensities involving different vascular territories on brain MRI. Diagnosis of CNS-IRIS is based of laboratory and radiologic findings, however brain biopsy is supportive. Despite immune restoration being involved in clinical deterioration, discontinuation of cART is not recommended. The use of corticosteroids is highly controversial. Prompt recognition of CNS-IRIS is crucial for preventing neurological complications and ensuing sequelae.