The scientific community invests significant resources on HIV/AIDS research to confront the current epidemic. We reviewed the medical literature in order to evaluate the contribution of different world regions on HIV/AIDS research during the past 18 years. We retrieved articles, using an elaborate methodology, from three journals focusing on HIV/AIDS between 1986 and 2003, indexed in the Journal Citation Reports (JCR) and the Web of Science databases of the Institute for Scientific Information (ISI). Comparisons were made by dividing the world into nine geographic regions, and by using the human development index (HDI) categorization. A total of 9502 articles on HIV/AIDS were retrieved from three AIDS journals over an 18-year study period. The United States and Western Europe together and five developed out of nine world regions made up a striking 83% and 92% of the world's research production on HIV/AIDS, respectively. Scientists from the developing world participated in 10.4% of the articles published during 1986-1991, 14.7% during 1992-1997, and 21.3% during 1998-2003. Researchers from countries included in the high, medium, and low HDI category produced 2240, 9, and 15 articles per billion population, respectively. About half of articles originating in Latin America and the Caribbean and half in Asia were produced in collaboration with the United States. However, 40% of articles from Africa and 58% from Eastern Europe were produced in cooperation with Western Europe. Collaboration between researchers within developing regions was negligible. The vast majority of the world's research on AIDS is produced in the developed world. Although research production was minimal in the developing world, we found that regions included in the low and medium HDI categories showed a higher proportion of increase in research productivity than the developed countries. International collaborations should significantly increase and expand beyond the traditional cultural and political lines of international relationships.