Production of bacteria and protistan bacterivory were measured in three reservoirs of different trophy: mesotrophic Lake Arlington (Texas, USA), meso-eutrophic Rimov Reservoir (South Bohemia, Czech Republic), and eutrophic Sau Reservoir (Catalonia, Spain). Protists, especially heterotrophic nanoflagellates (HNF), consume most of bacterial production (50-100 %) in all 3 reservoirs over an annual cycle, except for the short clear-water phase. However, with increasing trophy of the systems, ciliates become as important bacterivores as HNF. Despite large differences in reservoirs characteristics, basically the same taxonomic groups of HNF (chrysomonads, bodonids and choanoflagellates) and ciliates (small oligotrichs dominated by Halteria grandinella, vorticellids and scuticociliates) were found to be the principal bacterioplankton consumers.