The dataset aggregates the results from a pan-European multi-site experiment, financially supported by the ALTER-Net consortium, Europe’s Ecosystem Research Network. In this multi-site experiment, the impact of dung beetle assemblages on dung decomposition and secondary seed dispersal was studied. Working at a multi-site level allowed us to study the link between ecosystem functions of dung removal and secondary seed dispersal, and dung beetle diversity and abundance in a broad range of bioclimatic zones. Therefore, grazed grasslands throughout the Western Palaearctic zone were included in the experiment. By experimentally manipulating the access of certain dung beetle functional groups to the experimental units, we were able to estimate the value of each functional group for ecosystem functioning and assess the impact of predicted climate change on these processes through the changes it induces in dung beetle assemblage composition. During the experiments, the removal of different types of dung and seeds were measured and the dung beetle assemblage composition was determined using different types of dung as bait. The experiments took place between 2013 and 2016, at 17 study sites in 10 countries within the Western Palaearctic realm. The dung beetle occurrence data set contains all dung beetle specimens sampled during the 4-week experimental periods at each sampling site. To allow anyone to use this dataset, we have released the data to the public domain under a Creative Commons Zero waiver (http://creativecommons.org/publicdomain/zero/1.0/). We would appreciate however, if you read and follow these norms for data use (http://www.inbo.be/en/norms-for-data-use) and provide a link to the original dataset (https://doi.org/10.15468/zbazdy) whenever possible. If you use these data for a scientific paper, please cite the dataset following the applicable citation norms and/or consider us for co-authorship. We are always interested to know how you have used or visualized the data, or to provide more information, so please contact us via the contact information provided in the metadata, opendata@inbo.be or https://twitter.com/LifeWatchINBO.