The Bastyr University AIDS Research Center was established in October 1994 through a 3-year cooperative grant with the Office of Alternative Medicine, National Institutes of Health. The mission of the Center is to (1) describe forms and patterns of use of alternative medical therapies for HIV infection and AIDS prescribed by practitioners and self-administered by HIV-positive patients in the United States, (2) screen and evaluate therapies for HIV/AIDS from five program areas of alternative medicine, and (3) provide consultation and support in the scientific evaluation of alternative therapies. To meet these goals, the Center has established a network of cooperating alternative medicine clinics and is recruiting HIV-positive men and women who are using alternative medicine to participate in the study. It is collecting data every 6 months from 1500 HIV-positive patients throughout the United States and has created a centralized database to compare outcomes (CD4+ lymphocytes, HIV RNA, CDC class progression, weight, quality of life, and survival) for a variety of alternative therapies. The Center will determine whether patients who use both conventional medicine and alternative medicine have different outcomes from patients who use only conventional medicine. The occurrence of AIDS-related opportunistic infections and neoplasms in HIV-positive patients who are using specific alternative therapies will be compared with the incidence in those who use other medical treatment. This article describes the scientific plan for the study.