The present study was conducted to determine the parasitic infection with intestinal nematode species Nematodiruis spp. of sheep slaughtered in different areas from the slaughterhouses of Basrah, Iraq. Three hundred sixty sheep were examined during 2019- 2020. The nematodes were isolated from small intestine and kept into alcohol / glycerin for further diagnosis. It is worth commending that the diagnosis of Nematodiruis species was confirmed through the nomenclatural acts and registered in the Iraqi Natural History Research Center when a deposit number for Nematodes (sheep) Nematodiruis filicollis (Rudolphi, 1805) F: Anoplocephalidae: (INHM. 2020 Nem. 1.2). When the samples of nematodes were deposited in the helminth collection at the Museum of the University of Baghdad, this repository is considered as a confirmative for diagnosis and morphological analysis. Mixed infection with other parasites were reported with Moniezia spp., and significant increases were reported with Cystericus tenuicollis that considered importantly associated with Nematodirus infestation among the examined sheep. For our knowledge, this study is the first Iraqi report associated with confirmation of adult Nematodirus filicollis parasite in sheep.