Changes in policies and built environments are advocated as part of efforts to increase physical activity, but in 2001 the knowledge base to inform these changes was limited. The Robert Wood Johnson Foundation addressed this deficit by initiating Active Living Research (ALR). The mission of ALR was to stimulate and support research that could guide the improvement of environments, policies, and practices to promote active living. The program’s goals were to (1) build the evidence base about environmental and policy factors related to physical activity, (2) build the capacity of researchers in multiple fields to collaborate, and (3) inform and facilitate policy change. To build the evidence base, 121 grants were supported with $12.5 million. Efforts were made to support new investigators, fund investigators from numerous disciplines, and increase the demographic diversity of researchers. Activities to build capacity to conduct collaborative research included annual conferences, journal supplements, seminars for multiple disciplines, and the posting of environmental measures. Coor- dination with Active Living Leadership was a primary means of communicating research to policymakers. Other activities to facilitate the application of research included research summaries written for nonresearchers, collaborations with Active Living by Design, several components of the website (www.activelivingresearch.org), and using policy relevance as a funding criterion. Two independent evaluations were accomplished, and they concluded that ALR made progress on all three goals. ALR has been renewed through 2012. The new mission is to use a $15.4 million research budget to contribute to reversing the childhood obesity epidemic, especially among youth in the highest-risk groups.