The poorly known, so called widely distributed and highly varying species of the European Rhyacophila fasciata species complex are revised by fine phenomics of the paramere organisation. In this species complex paramere is the most diverse organ. It is the speciation trait integrating the initial split of speciation by its stimulatory and titillating function involved in the early processes of reproductive isolation. Based on paramere organisation and on the character state of distribution three lineages have been delineated in the Rhyacophila fasciata species complex: the European R. fasciata lineage, the Caucasian R. aliena lineage and the R. mysica lineage distributed from Albania to Pakistan. In the R. fasciata lineage we have distinguished three clades of species: R. fasciata with five species, R. matrensis with seven species, and R. denticulata with seven species. We have re-diagnosed three known species: R. fasciata Hagen, 1859, R. denticulataMcLachlan, 1879, R. sociata Navas, 1916 and described 15 species new to science: R. biharensis Oláh sp. nov., R. bulgarica Oláh sp. nov., R. coppai Oláh sp. nov., R. csornahorensis Oláh & Szczęsny sp. nov., R. ferda Oláh sp. nov., R. kopasa Oláh & Coppa sp. nov., R. matrensis Oláh, & Szczęsny sp. nov., R. retezatensis Oláh sp. nov., R. rova Oláh & Coppa sp. nov. R. ruda Oláh & Johanson sp. nov., R. salfa Oláh sp. nov., R. soreda Coppa & Oláh sp. nov. R. suna Oláh sp. nov., R. tuhega Oláh sp. nov., R. zemplenensis Oláh sp. nov. The species status of Rhyacophila gemella Navas, 1923 was reinstated.