Part 4 is the final part of a revision of the western palaearctic Nephrotoma species. A key to these species is presented. Discussed are the species N. analis (Schummel, 1833), N. euchroma (Mik, 1874), N. subanalis (Mannheims, 1951), N. semiflava (Strobl, 1909), N. lamellata (Riedel, 1910), N. flavipalpis (Meigen, 1830), N. malickyi Martinovský, 1979, N. alluaudi (Pierre, 1921), N. eugeniae (Savchenko, 1957), N. lundbecki (Nielsen, 1907), and N. ramulifera Tjeder, 1955. Furthermore four species erroneously referred to Nephrotoma, or recorded thus from the western palaearctic are discussed.