Research impact on various societal spheres has been increasingly demanded for funding purposes and as a form of demonstrating the relevance of scientific research for societal problems. In this context, interest in interdisciplinary research and knowledge coproduction has grown as a path to achieve this expected impact, but few studies have considered its conjoint association with societal impact. This article investigates how academic research undertaken in interdisciplinary groups impacts public policies. To this end, we used a multiple case study strategy (involving three broad interdisciplinary research groups) to understand how the differences regarding knowledge coproduction with policy actors were relevant to explain differences in research impacts: instrumental, conceptual, symbolic and capacity-building. All the groups studied presented some type of impact in public policies, with emphasis on conceptual impact. The importance of knowledge coproduction was highlighted in two broad interdisciplinary groups since they stood out with more instrumental impacts compared to the other one. We argue that the combination of broad interdisciplinarity of the group together with the coproduction of knowledge with policymakers as co-researchers produces research that has more impact on the public policy community, especially translated as instrumental impact.