If research addresses the questions of relevance to patients and clinicians, decision-makers will be better equipped to design and deliver health services which meet their needs. To this end, a number of initiatives have engaged patients and clinicians in setting research agendas. This paper aimed to scope the research literature addressing such efforts.A systematic search strategy combined electronic searches of bibliographic databases with handsearching and contacting key authors. Two researchers, initially working independently, described the relevant reports.Over 250 studies addressed patients' or clinicians' priorities for research and outcomes for assessment. This literature described different routes for patients and clinicians to contribute to research agendas. Two-thirds of the studies addressing patients' or clinicians' research questions were applicable across health care, with the remainder focussed on specific health conditions. The 27 formal studies of patient involvement revealed a literature that has grown in the last decade. Although only nine studies engaged patients and clinicians in identifying research questions together, they show that methods have advanced over time, with all of them engaging participants directly and repeatedly in facilitated debate and most employing formal decision-making procedures.A sizeable literature is available to inform priorities for research and the methods for setting research agendas with patients and clinicians. We recommend that research funders and researchers draw on this literature to provide relevant research for health service decision-makers.