The aim of this review was to undertake a survey of researchers working with plant-parasitic nematodes in order to determine a 'top 10' list of these pathogens based on scientific and economic importance. Any such list will not be definitive as economic importance will vary depending on the region of the world in which a researcher is based. However, care was taken to include researchers from as many parts of the world as possible when carrying out the survey. The top 10 list emerging from the survey is composed of: (1) root-knot nematodes ( Meloidogyne spp.); (2) cyst nematodes ( Heterodera and Globodera spp.); (3) root lesion nematodes ( Pratylenchus spp.); (4) the burrowing nematode Radopholus similis ; (5) Ditylenchus dipsaci ; (6) the pine wilt nematode Bursaphelenchus xylophilus ; (7) the reniform nematode Rotylenchulus reniformis ; (8) Xiphinema index (the only virus vector nematode to make the list); (9) Nacobbus aberrans ; and (10) Aphelenchoides besseyi. The biology of each nematode (or nematode group) is reviewed briefly.