In the cooperation of seven running H2020 geothermal projects, the workshop “Geochemistry of Geothermal Fluids” was organised at university of Miskolc, Hungary, on 26-27 October. The aim of the workshop was to bring together the representatives of these projects who are interested in the geochemical aspects of the geothermal energy production and provide them with a forum for discussion. Beside the project representatives, there were also participants from other institutions; altogether 34 experts from 10 countries attended the workshop. On the first day, the seven represented H2020 projects were introduced, with a special focus on the geochemical component. This was followed by other presentations related to the theme of the workshop. On the second day, there was a moderated discussion on the questions and problems raised on the former day, then the participants discussed the possibilities of potential future cooperation under the 2018-2020 period of the H2020 calls. The presentations of the workshop are available here.