To combat the HIV epidemic, health service providers and public health professionals must use the best possible science and proven program models to reach and influence HIV-positive individuals and others at high risk of becoming infected. The large number and complexity of approaches that are necessary to institute and maintain HIV prevention programs make capacity-building for effective positive health outcomes essential. Capacity-building is a dynamic and informative process intended to improve the skills of individuals, organizations, and communities. It focuses on strengthening the knowledge and skill sets of both providers and recipients of health services. Capacity-building may also lead to the development of systems, such as communities or organizations, that are better able to address health problems, and in particular, problems that arise out of social inequity and social exclusion. This document explores the ways in which capacity-building can be applied to health promotion and disease prevention programs that focus on HIV by addressing the following questions: (1) What is HIV prevention capacity-building?; (2) Why build capacity?; (3) What is distinctive about capacity-building?; (4) Why invest in capacity-building?; (5) Will building capacity make a difference?; and (6) How does capacity-building affect sustainability? Appended are: (1) Annotated Bibliography; (2) Glossary; and (3) Acronyms. (Contains 1 table, 2 figures and 9 footnotes.)