At the time of the first aids cases in 1981 in the United States, no one could have predicted that it would signal the start of a worldwide epidemic. To mark World Aids Day, this journal is devoting a special issue to HIV/AIDS. Erroneously, it seems that in the Netherlands HIV/AIDS is sometimes forgotten. Among men who have sex with men, the HIV incidence is around 1%--a rate that is just as high as that among adults in many African countries. In order to slow down the spread of the virus, there should be more intensive testing for HIV, by, for example, 'opting out'. Developments in the field ofHIV/AIDS outside the Netherlands are also discussed. There is an article on a successful HIV/AIDS treatment project setup by Médicins sans Frontières in the Ukraine. The consequences of the large-scale availability of antiretroviral drugs in developing countries are also examined. Because of these programs increased resistance of the virus to the medication may become a problem. Further, a promising initiative to improve the financing of healthcare systems in Africa is discussed. An effective vaccine for HIV seems far away. Recently, Merck halted the development of an HIV vaccine based on T cell immunity, because the clinical results were disappointing. Waning interest in investing in an HIV vaccine from the pharmaceutical sector means that governments will have to increasingly take on this role. For now strategies for the prevention of HIV must be to continue to stimulate safe sexual behavior, good diagnostic and treatment services for sexually transmitted infections, and more and earlier HIV testing.