In 2011, an interdisciplinary symposium was organized in Toronto, Canada to investigate prevailing models of health policy change in the knowledge translation literature and to assess the applicability of these models for equity-focused urban health research. The papers resulting from the symposium have been published together, in the Journal of Urban Health, along with this introductory essay. This essay describes how the different papers grapple in different ways with how to understand and to bridge the gaps between urban health research and action. The breadth of perspectives reflected in the papers (e.g., social epidemiology, public health, political science, sociology, critical labor studies, and educational psychology) shed much light on core tensions in the relationship between KT and health equity. The first tension is whether the content of evidence or the context of decision making is the strong determinate of research impact in relation to health equity policy. The second tension is whether relationships between health equity researchers and decision makers are best viewed in terms of collaboration or of conflict. The third concerns the role that power plays in evidence-based policy making, when the issues at stake are not only empirical but also normative.