Large population densities (more than 100 000 per g dry weight of roots) of Radopholus nativus apparently caused economic damage to wheat near Wyalkatchem, Western Australia. Plants in large areas of poor growth were colonised by R. nativus, whereas in areas of better growth Pratylenchus neglectus occurred at lower population densities. The boundary between the areas was distinct. In the same year (1998), a further nine wheat samples were found to be infested with R. nativus through examination of 300 diagnostic samples submitted by Western Australian growers. Mixed Radopholus/Pratylenchus populations occurred in six of those samples. Populations of R. nativus were widely dispersed throughout the cropping areas of the State. It is concluded that R. nativus has the potential under certain conditions and/or crop rotations to reach high population density and cause economic loss.