HIV/AIDS is a new epidemic in current century. Predominant route of transmission is sexual. Virtually all systems are affected either directly by virus or by oppurtunistic infections or by malignancy. Neurological complications may occur at any stage of disease. Clinical manifestations may be acute, subacute or chronic. Presentation and diagnosis are often confusing. Central nervous system toxoplasmosis and tuberculous meningitis are commonest opportunistic infections in advanced HIV patients. Patients frequently present with focal neurodeficit. Mortality is high i.e., 13 (54%) out of 24 cases of opportunistic infectious in the study carried out at the SSKM Hospital during the period January 2005 to December 2006.