The evidence-based policy (EBP) movement has sought to promote rigorous analysis of service programs and policy options in order to improve the quality of decision-making. Rigorous research findings are seen as useful and necessary inputs for policy-makers in their ongoing consideration of policy development and program review. This article provides a critical overview of the research literature on evidence-based policy in the context of government policy-making and program improvement. Particular attention is given to the rational expectation that improved policy analysis will flow from a better evidence base, with consequent improvements in the service delivery and problem-solving capacities of government agencies. This expectation is contrasted with the practical limitations on rational processes typical in the real world of political decision-making, which is characterised by bargaining, entrenched commitments, and the interplay of diverse stakeholder values and interests. Key issues for consideration include the forms of evidence that are of greatest relevance or utility for decision-makers, and the most productive forms of interaction between the producers and the users of research and evaluation findings.