Despite the growing expectation that researchers report the impact of their research using a case study approach, systematic reviews of research impact have focused on frameworks, indicators, methods of data collection and assessment rather than impact case studies. Our aim is to provide an overview of the characteristics of published research impact case studies, including translation activities, and their reporting quality. We searched for peer-reviewed impact studies published between 2000 and 2018 using a case study approach and selected 25 suitable papers. We applied descriptive statistics to study characteristics, conducted thematic analysis of research translation activities and assessed reporting quality using the 10-point ISRIA statement. 24 papers reported intermediate impacts, such as advocacy, or the development of statements, tools, or technology. 4 reported on longer-term societal impacts, such as health outcomes and economic return on investment. 7 reported on translation activities. Papers scored well against the ISRIA statement on 5 domains of reporting quality. Weakest scores centred around identification of stakeholder needs and stakeholder involvement, and ethics and conflict of interest. We identified the need for more consistency in reporting through a case study approach, more systematic reporting of translation pathways and greater transparency concerning estimated costs and benefits of the research and its translation and impact assessment.