A new species of the dagger nematode genus Xiphinema was recovered from three different points in West Azarbaijan province, northwestern Iran, from the rhizosphere of grasses and described based on both morphological and molecular data. Xiphinema azarbaijanense n. sp. belongs to the Xiphinema non-americanum group and is characterized by having 3.8-5.3 mm long females with long odontostyle (129-151 µm), two equally developed genital tracts with crystalloid bodies in the tubular part of uterus, short tail, four juvenile developmental stages and males absent. It is similar to 14 known species belonging to morphospecies group 6, and is almost indistinguishable from most of them using traditional taxonomy; thus, is part of a complex of cryptic species. Molecular phylogenetic data using two genomic structural (18S, 28S D2-D3) and one ITS1 ribosomal DNA (rDNA) loci were used to separate the new species from close taxa. The new species formed an independent lineage in three reconstructed trees based upon the resolved topologies, and was also morphologically compared with phylogenetically related species.