Abstract Background The collaborative research between EUPHA and WHO aimed to explore factors impacting public health professionals’ (PHP) involvement in health policy processes in the Eastern WHO European Region, addressing barriers, enablers, and capacity-building needs. Methods Utilizing a mixed methodology, the study employed document analysis, scoping review, and interviews to triangulate data, with the document analysis focusing on 4 published Essential Public Health Operations Self-Assessment Reports, the scoping review analysing 15 key articles, and 5 semi-structured interviews providing additional insight from key country stakeholders. Results Core findings revealed significant barriers impeding PHPs' participation in policy processes. Among others, these included limited intersectoral collaboration, shortage of skilled public health (PH) personnel, financial resource constraints and inadequate governance structures. Conversely, several enablers were identified, such as a positive trend in increased intersectoral collaboration and innovative governance structures during Covid-19, the development of more trained PHPs and the utilization of International Health Organisations. The two main capacity building needs reported were the importance of modernizing PH education and promoting intersectoral collaboration. Conclusions This study offers a preliminary overview of how PHPs' involvement in health policy processes in these countries can be enhanced: More intersectoral collaboration, updated PH education curricula and trainings, and governance re-design building on positive trends seen during the pandemic. Following actions are recommended: Creation of an international platform for cross-sectoral PH communication & exchange, direct support for universities and PH researchers, development of comprehensive PH trainings, assistance in forming or strengthening national public health associations and identification & sharing of effective local governance practices. Key messages • This research identifies barriers to PHPs’ participation in Eastern WHO European Region's health policy processes, while highlighting enablers like increased collaboration during Covid-19 to build on. • Recommendations to harness the enablers include clear actions such as creating an international public health platform for interaction and exchange or build-up of national public health associations.