The present update to the data base incorporates all available epidemiological information for developing countries presented at the following Conferences on AIDS, 4th International Congress on AIDS in Asia and the Pacific, Latin American Congress on Sexually Transmitted Diseases, and Xth International Conference on AIDS and STD in Africa. Currently the HIV/AIDS Surveillance Data Base contains about 39,769 individual data records drawn from 4,371 publications and presentations. It is our goal to incorporate all available data from seroprevalence studies conducted in developing countries.