This application seeks continuation of funding for the Minority Populations Prevention Researcher Training Program (MPPRT) at the University of California San Francisco (UCSF). This training program addresses the urgent need for multidisciplinary programs of research targeting individual-, interpersonal-, and structural-level influences on HIV, other sexually-transmitted infections (STIs), and sexual and reproductive health (SRH) among U.S. vulnerable populations. The MPPRT program provides research education and mentoring too early- career social and behavioral scientists who have demonstrated cultural expertise, a commitment to improving the health of underserved/vulnerable minority populations, and who are initiating innovative programs of research to advance the NICHD's HIV/STI- and SRH-related objectives. The aims of this five-year project are to: 1) Build capacity among visiting professors (VPs) to conduct multidisciplinary social/behavioral HIV/STI and sexual and reproductive health (SRH) disparities research involving structural, social, cultural, and individual factors affecting HIV/STI- and SRH-related disparities; 2) Provide funding and mentoring to VPs to design and conduct innovative pilot research that will be presented at conferences, lead to publications, and inform subsequent federal grant proposals; 3) Provide education, mentoring, and assistance to VPs in the writing, submitting, revising, and resubmitting of federal grants focused on social/behavioral HIV/STI and SRH disparities research; and 4) Provide peer review and consultations to VPs who have completed the program to help them continue their innovative programs of HIV/STI and SRH disparities research as independent investigators and mentors. The centerpiece of the proposed program will be an intensive summer training program for VPs who have not yet obtained R01-level funding. Each VP will be at CAPS for six weeks for three consecutive summers. In the first summer, the program will help VPs develop their ideas into feasible programs of research and design and implement a pilot study funded by the program. During the academic year between the first and second summers, they will collect pilot data. During the second summer, they will analyze the pilot data and begin an NIH grant proposal. Following the second summer, VPs will present their pilot results at a conference and draft manuscripts for publication and continue to work on their grant proposal drafts. In the third summer, VPs will complete their proposals and submit them to NIH. The MPPRT program will leverage the unique environment at CAPS to provide tailored research education and mentoring, assist program participants to become successful independent investigators, and help retain these outstanding scientists, many of whom are from underrepresented groups, in the research pipeline.