The HIV/AIDS pandemic marks a severe development crisis in Africa, which remains by far the worst affected region in the world. Forty-two million people now live with HIV/AIDS of which 29.4 million (70.0%) are from sub-Saharan Africa. Approximately 5 million new infections occurred in 2002 and 3.5 million (70.0%) of these were also from sub-Saharan Africa. The estimated number of children orphaned by AIDS living in the region is 11 million. In 2002, the epidemic claimed about 2.4 million lives in Africa, more than 70% of the 3.1 million deaths worldwide. Average life expectancy in sub-Saharan Africa is now 47 years, when it would have been 62 years without AIDS. HIV/AIDS stigma is still a major problem despite the extensive spread of the epidemic. A complex interaction of material, social, cultural and behavioural factors shape the nature, process and outcome of the epidemic in Africa. However, too many partners and unprotected sex appear to be at the core of the problem, Even if exceptionally effective prevention, treatment and care programmes take hold immediately, the scale of the crisis means that the human and socio-economic toll will remain significant for many generations. Although 70% of people living with HIV/AIDS are in Africa, only 6,569 (4.7%) of the 140,736 scientific publications on HIV/AIDS, from 1981 to 2000, are directly related to Africa. Effective responses to the epidemic require a multisectoral approach, including governments, the business sector and civil society.