The second EU BON stakeholder round table took place on 27th November 2014 at the Museum für Naturkunde in Berlin. The workshop was dedicated to explore ways in which EU BON can support citizen science (CS) activities. As EU BON is building a large integrated biodiversity information infrastructure in order to serve science, policy and administration, citizen science and related projects and networks are important stakeholders. Furthermore, citizen scientists can play an essential role, as they support the increase of knowledge in various aspects, they may debate research questions, most often they collect data, and they may interpret data and publish their results. At the stakeholder round table in Berlin, various stakeholders from the field of citizen science were invited to discuss possibilities of interactions and the role of EU BON for supporting citizen science on a European scale (with the EU BON data portal, standardization of data and data collection standards, visualization/interpretation of data and guidelines). The discussions and break-out groups gave valuable impulses for the development of the EU BON portal and Citizen Science gateway, for data mobilization from different communities, and the linkage to the European Citizen Science Association (ECSA) and its activities.