Systematic literature syntheses are a key element in the scientific realm, considering the steadily growing amount of available knowledge. Involving stakeholders in the research process brings a wide range of advantages, like broadening the perspectives on the problem in question, increasing the relevance of results for policy- and decision-making, the public and other end-users and thus enhancing the impact and acceptance of research. While participatory approaches are on the rise, reflections on stakeholder involvement in systematic syntheses on environmental management are scarce. We reflect on the process of involving stakeholders with expertise also from outside academia during three literature syntheses with different foci of marine and coastal ecosystem services in the Baltic Sea. Our analysis is based on notes, e-mails, minutes and recordings of internal project meetings, interviews and workshops involving both researchers and stakeholders. We discuss the challenges the participatory approach introduced and develop lessons learned to support the planning of stakeholder engagement for future literature syntheses. We conclude that stakeholder identification, communication, collaboration and knowledge translation are highly time- and resource-intensive processes. Furthermore, appropriate training and experience are necessary for the design, execution and evaluation of participatory methods tailored to each project stage. Therefore, we underline the importance of adequate consideration of the required resources during project planning and implementation. To encourage and support valuable stakeholder engagement and knowledge exchange between the research community and actors of policy and practice, more appreciation of such efforts by funding institutions and within the wider scientific community is needed.