Efforts to improve population health have always been associated with social action. Within science, however, there exists a tension as to whether including an advocacy agenda in research distorts the objective, impartial process that scientific inquiry is expected to pursue. Action-related research models such as, participatory action research (PAR) and community-based participatory research (CBPR), have been strengthening the case for melding rigorous research with generation of knowledge that informs practice and policy and contributes to social change. In order to adequately carry out evidence-based activities and assess their impact, three important factors must be present: (1) methodologic rigor; (2) resources for postresearch evaluation; and (3) acceptance by the scientific community that advocacy is an appropriate role for researchers. This article describes several studies that reflect advocacy concerns while utilizing research methods that followed scientific conventions, even leading to findings that were not what advocates might have anticipated.