The Robert Wood Johnson Foundation requested this utilization-focused evaluation of its Active Living Research (ALR) program. This evaluation reports on the trajectory of influence of past and future ALR outcomes on field-building and policy contributions as well as on possible users of completed and disseminated ALR products. In 2006 and 2007, key-informant interviews were conducted with 136 representatives of first-line potential users of ALR research products, including state physical activity and nutrition program coordinators, policymakers, scientists, and funders. Literature reviews, bibliometric analyses, and document reviews served to describe the context for ALR’s work and the ways it could enhance its utility for field building and policymaking. The contributions of ALR to the emerging transdisciplinary field included leadership in the development of measurement tools, epidemiologic studies, implementation research, the translation of research to practice, and the communication of learned lessons to diverse audiences. ALR’s contributions to policy discussions were found across a spectrum of policy-development phases that included describing the problem, raising awareness of alter- native strategies for increasing physical activity, convening nontraditional partners, and evaluating policy implementation. Policy-relevant research can make contributions to policymakers’ thinking but almost never causes a change by itself. Five years after the original authorization of ALR, there is ample evidence of its recognition as a resource by key players, its field-building influence, and its contributions to policy discussions. All these bear promise for a broader contribution to obesity prevention. Recommendations for increasing ALR’s impact on policy and practice are offered.