An evaluation was undertaken of the initial 6 years of the Active Living Research (ALR) program. Conducted in 2006 and analyzed in 2007, the evaluation was designed to assess productivity and progress on all three program goals and to inform consideration of program re-authorization. The evaluation was a retrospective, in-depth, descriptive study utilizing multiple methods, both qualitative and quantitative. Qualitative data were derived mainly from 88 interviews with key informants. Quantitative data were derived primarily from a web-based survey of grantee investigators. Examples of key indicators of ALR's progress in addressing its goals were (1) in building a knowledge base: 40% of grantee investigators reported producing at least one scientific publication based on their ALR study, averaging two papers per principal investigator who had published; (2) in growing a transdisciplinary field: investigators funded in the first five rounds of grants reported representing more than 20 disciplines; and (3) in contributing to policy change: ten examples were reported of contribution to specific policy changes. In addition, more than one-third (37%) of principal investigators had leveraged additional funds, averaging $275,000 per ALR grant, suggesting that ALR also had made progress in growing financial resources for the field. Overall, ALR made strides during 6 years in addressing its mission to develop a transdisciplinary field of research on environmental and policy factors that promote physical activity. The evaluation provided insight into useful approaches and strategies for building a nascent research field and suggested how to enhance the contribution of research to policy.