This is the first paper to comprehensively describe the community structure of Scarabaeoidea dung beetles attracted to European bison dung, including their diel activity. The beetle community was monitored during six research series (April to October) in Białowieża Primeval Forest, Poland (≈160 m elevation). The study material comprised 6,401 individuals representing 20 species. Diurnal communities were dominated by Anoplotrupes stercorosus (Scriba), while Aphodius rufipes (L.) was the only species with most of the individuals caught at night. The latter dominated overnight communities in June and August. Patterns of diel activity of most of the taxa seem to be stable during the whole season.