Objectives: There have been calls for greater exchange between research and practice in health care policy and management, but little empirical research on what commissioners of research and researchers themselves consider appropriate, good quality research knowledge. This paper addresses this gap, considering the views of commissioners and producers of policy and management research in health care and other fields. Methods: Qualitative semi-structured interviews with 18 commissioners and producers of research, in central government, theNHSand other commissioning organizations, and in universities and independent sector providers. Results: Commissioners and producers agreed that research often fails to fulfil policy-makers' and managers'needs, and that greater interaction is required to improve this relationship. However, they offered differing accounts of the nature of research knowledge (as a 'product' or a 'mindset'), and of what constitutes value, validity and originality in research, reflecting the differing priorities and pressures faced by the two groups. Conclusions: Efforts to promote greater interaction between research, policy and practice, and more critical, reflexive engagement between policy-makers, managers and researchers, are likely to face significant obstacles given these competing constructions of research knowledge and their reinforcement by divergent priorities.