The central nervous system is involved in two thirds of HIV cases and 90 % of autopsy specimens. It is the first manifestation of HIV in 10 % of cases. The changes can be caused directly by HIV itself or due to immunosuppression induced opportunistic infections, secondary tumours and vascular lesions.  The prevalence is less in the earlier stages of HIV , due to advent of antiretroviral drugs. The prevalence is higher in the later stages of immunosupression. Neuroimaging plays a vital role in the diagnosis and management , since the clinical symptoms and signs are non specific and serological testing is neither sensitive or specific. MRI is the imaging modality of choice since it has a higher sensitivity and contrast resolution than CT scans. Gadolinium is administered when there is a lesion in T2W images , to increase the diagnostic specificity. Location, mass effect and contrast enhancement are features which help in narrowing the differential diagnosis. CT scan is used as a screening tool and is often used before lumbar puncture. Spectroscopy, PET and functional imaging are helpful in suspicious cases to increase specificity.