The objective of the study “Assessing the reproducibility of research results in EU Framework Programmes for Research” is to assist the European Commission in understanding, testing and monitoring the progress of reproducibility over time and across the programmes. The study primarily focused on the state of reproducibility during the implementation of Horizon 2020. The study relied on a mixed-methods research design, combining qualitative textual analysis of 50 Horizon 2020 projects, quantitative assessment of 300 Horizon 2020 projects, as well as a large-scale survey programme of researchers, journal editors, and research funders. The data collected indicates that while reproducibility of research is an important principle to stakeholders overall, the level of implementation of reproducibility-related practices is very mixed depending on the specific reproducibility-related factor. Our findings suggest that the key barriers for reproducibility are cultural factors in the scientific field (e.g. pressure to publish, lack of recognition of reproducibility-related research practices) and the perception that reproducibility is costly in terms of time and resources. Based on these findings, this study provides a comprehensive set of recommendations for research funders to overcome the existing barriers and increase reproducibility of EU-funded research and innovation.