Dementia remains one of the most fearsome complications of HIV infection. It also poses a significant challenge for the clinician both in terms of diagnosis and treatment. The use of antiretroviral agents has led to a decrease in the incidence of HIV dementia but the prevalence of milder forms of neurocognitive impairment has increased. Occasionally, the immune reconstitution caused by these agents may target the brain leading to a syndrome characterized by a severe, progressive and often fatal dementia. The progression of HIV dementia may also be determined by host and viral genetic factors, and the existence of co-morbid factors such as drug abuse, hepatitis C infection and aging. Oxidative stress markers appear to be predictive of active dementia. However, currently there is no specific treatment available for HIV dementia.