The annelid family Eunicidae comprises ten genera including the genusMarphysa Quatrefages, 1866. This genus is characterized by a global distribution and hasconsiderable value in the bait industry worldwide. Therefore, the correct delimitation ofspecies is important not only for consideration of its evolution, but also for culturing speciesfrom this genus. Marphysa sanguinea (Montagu, 1813) represents a complex of species andits global distribution is not clearly defined. Herein we describe a new species, Marphysaaegypti sp.n., belonging to the M. sanguinea group from the coastal waters of Egypt. Thisspecies, which has previously been reported as M. sanguinea, has a high commercial valueas it is collected and vastly used by fishermen in Egypt. In our study, we used both molecular(COI barcoding region) and morphological species identification. Our results confirm thatthis polychaete, which is a common inhabitant of Egyptian coastal waters (i.e., Mediterra-nean Sea, Red Sea and the Suez Canal), is a distinct species. Our findings further supportthe view that the polychaete fauna of Egypt needs taxonomic revision. Determination of thepolychaete species of Egypt, similarly to other regions of the world, is based on identifica-tion keys developed for Northern European species and lacks thorough morphologicalcomparisons. Therefore, all previous records of M. sanguinea in coastal waters of Egyptshould be reconsidered as being indeed M. aegypti sp.n.