Acknowledging the growing disparities in health and health care that exist among immigrant families and minority populations in large urban communities, the UCLA Department of Family Medicine (DFM) sought a leadership role in the development of family medicine training and community-based participatory research (CBPR). Performing CBPR requires that academic medicine departments build sustainable and long-term community partnerships. The authors describe the eight-year (2000-2008) process of building sustainable community partnerships and trust between the UCLA DFM and the Sun Valley community, located in Los Angeles County.The authors used case studies of three research areas of concentration (asthma, diabetes prevention, and establishing access to primary care) to describe how they established community trust and sustained long-term community research partnerships. In preparing each case study, they used an iterative process to review qualitative data.Many lessons were common across their research concentration areas. They included the importance of (1) having clear and concrete community benefits, (2) supporting an academic-community champion, (3) political advocacy, (4) partnering with diverse organizations, (5) long-term academic commitment, and (6) medical student involvement. The authors found that establishing a long-term relationship and trust was a prerequisite to successfully initiate CBPR activities that included an asthma school-based screening program, community walking groups, and one of the largest school-based primary care clinics in the United States.Their eight-year experience in the Sun Valley community underscores how academic-community research partnerships can result in benefits of high value to communities and academic departments.