Systems for assessing the comparative performance of organizations providing public services are increasingly apparent across service sectors and jurisdictions. This article sets out an agenda of research themes about these systems. The themes include the performance concepts and measures adopted, purposes of systems (with variation from information-gathering to incorporation in systems of judgement and decision-making by a range of stakeholders), the reasons for the increasing prevalence of the systems, and the impacts of systems on public services -both intended and unintended. The article argues that the comparative analysis of comparative performance systems is a valuable approach, with comparison looking across both jurisdictions and public service domains. While such analysis is currently at an early stage of development, drawing together the findings of the articles contained in this special issue illustrates some of the insights that can be gained into these themes.