Basic factual information about disease is the cornerstone of health promotion and disease prevention interventions. Previous studies have shown that content analysis of the questions asked of service providers can elucidate the information needs of service consumers. Questions asked by individuals at known high risk for HIV infection have not previously been examined. The current study analyzed 944 questions asked by 634 patients receiving HIV-risk-reduction counseling services at an urban sexually transmitted infections clinic. Questions were captured from audiotape recordings of risk-reduction counseling sessions that were subsequently transcribed and content-analyzed. A total of 49% of clients asked at least one question in their counseling session. Asking counselors questions was not associated with demographic characteristics or AIDS-related knowledge. Questions were found to fit the AIDS information content structure identified in past research. The most common questions asked by sexually transmitted infection clients concerned condoms and other barrier methods of prevention (15%), HIV symptoms and disease progression (14%) and HIV antibody testing (11%). These results show that many individuals at high risk for HIV infection have substantial information needs, and that basic education about AIDS facts should not be neglected in HIV prevention interventions. (Contains 2 tables.)