Kermanshah province with a cultivated area of 135,060 hectares is the second legume producer in Iran. As there wasn’t any comprehensive study on the identification of plant-parasite nematodes of legume fields in the province, this study was performed to identify the species of dominant plant-parasitic nematodes species of legume fields and to determine their distribution in Kermanshah province. For this purpose, 173 root and soil samples were collected from legume fields in several localities of Kermanshah province, during years 2016-2017. After extraction, fixation and transferring to anhydrous glycerol, the nematodes were mounted on microscopic slides and studied by the light microscope, equipped with digital camera. Based on morphometric and morphological characteristics, in this study 19 species of the infraorder Tylenchomorpha viz. Aphelenchoides graminis, A. obtusus, Aphelenchus avenae, Ditylenchus adasi, D. equalis, D. medicaginis, D. myceliophagus, D. parvus, Filenchus vulgaris, Helicotylenchus scoticus, Merlinius brevidens, Nagelus obscurus, Neopsilenchus magnidens, Pratylenchus thornei, Pratylenchoides ritteri, Scutylenchus rugosus, S. tartuensis, Trophorus ussuriensis and Tylenchorhynchus parvus were identified. The males of A. obtusus is reported for the first time from Iran.The species F. vulgaris, D. medicaginis, P. ritteri, H. scoticus, M. brevidens and T. parvus with 33.8, 29.4, 27.9, 26.5, 13.2 and 13.2 percent frequency rates, respectively, were the most common species in the legume fields of Kermanshah province. Among 12 cities under legumes cultivation in the province, Kermanshah with 16 species, Ravansar and Gilan gharb each with nine species, Eslam Abad and Kerend Gharb each with seven species, have highest number of the nematode species.