OBJECTIVE: The goal of this research was to evaluate changes over time in the capacity of participants of the CDC/ASPH Institute for HIV Prevention Leadership (Institute), a capacity-building program for HIV prevention program managers in minority-based, community-based organizations. Capacity was defined as the application of new skills and knowledge to participants' jobs and confidence in using those new skills and knowledge to strategically manage and apply "best practices" to their HIV prevention activities. METHODS: This is a longitudinal study involving measuring scholar capacity at three points in time: pre-Institute, post-Institute, and 6 months' post-Institute. Only responses from participants who completed all three surveys are included in this final analysis of the data (N = 94). RESULTS: Results indicate that participants from 3 years of the Institute (2002-2004) increased their capacity in HIV prevention programming and strategic planning and management. Significant changes were seen in the frequency and self-efficacy with which participants conduct several HIV prevention programming activities. Participants also reported conducting strategic planning activities at more appropriate intervals and were significantly more confident in conducting these activities. CONCLUSION: The Institute has positively and significantly increased the capacity of participants to conduct more effective HIV prevention programs on a national level. © 2007 Lippincott Williams & Wilkins, Inc.