Cognitive abnormalities may occur in the physically asymptomatic phases of the infection with the human immunodeficiency virus (HIV), and poor education may represent a risk factor for their development. These abnormalities are usually mild, and apparently do not affect subjects’ daily living performance, although this notion should be regarded as preliminary, due to the present primitive stage of development of the instruments which assess functioning in daily living activities. The above evidence has emerged from the cross-sectional phase of the WHO Neuropsychiatric AIDS Study, carried out in the five geographic areas predominantly affected by the HIV epidemic (sub-Saharian Africa, Latin America, North America, South-East Asia, Western Europe), on subject samples that are representative of the whole population of HIV-infected persons living in those areas. The professional implications of HIV-associated early cognitive dysfunction are open to research: for example the current debate on the impact of dysfunction on aviation-related skills emphasizes the need for test batteries with a higher predictive potential than those presently available.