Soil samples were collected from three native Iowa prairies and analyzed for plant paiasitic nematodes and selected soil properties. Sites or nematodes were clustered with similarities related to habitat by a cluster analysis of site by nematode species and of nematodes by site. Some nematodes occurred in a wide range of prairie habitats, whereas others were more restricted. For example, greater numbers of Xiphinema americanum were in the low, well-drained sites than in the low wet sites or upland dry sites. Wet sites contained fewer nematodes than well-drained sites. Well-drained sites contained mainly Tylenchorhynchus maximus, Helicotylenchus pseudorobustus, and X. americanum. Wetter sites contained almost exclusively X. chambersi, H. hydrophilus, Telylenchus ]octus, and an undescribed species of Tylenchorhynchus. Key words: habitat relationships, H. leiocephalus, Aorolaimus torpidus, T. nudus.