In order to identify the biodiversity of plant parasitic NEMATODES in vegetable fields of Tabriz, during 2004-2005, 88 soil and a few root samples were collected from rhizosphere of 25 dominantly cultivated vegetable crops. NEMATODES were extracted by combined sieving and centrifugal–flotation method and processed to be transferred to glycerin. After preparing microscopic slides, the morphological and morphometrical features of the NEMATODES were studied using the light microscope equipped with a drawing tube. The morphological features and measerments of the extracted NEMATODES were compared with those ones given in literature and similarities and differences with original descriptions and closest species were discussed. As a result, 25 species belonging to 16 genera including Amplimerlinius globigerus, Aphelenchus avenae, Aphelenchoides bicaudatus, A. haguei, A. richardsoni, Boleodorus thylactus, Criconema mutabile, Criconemoides informis, C. mongolensis, Ditylenchus medicaginis, Filenchus vulgaris, Geocenamus brevidens, G. rugosus, Helicotylenchus digonicus, H. exallus, H. pseudorobustus, H. vulgaris, Heterodera cruciferae, Mesocriconema antipolitanum, M. curvatum, Paratylenchus mexicanus, Pratylenchus alleni, P. neglectus, Psilenchus hilarulus and Zygotylenchus guevarai were identified. Most of the NEMATODES are already recoded from Iran and herein, three species namely, Aphelenchoides haguei, Aphelenchoides richardsoni and Pratylenchus alleni and one newly reported species (Helicotylenchus exallus) are described.