Examines the characteristics of suppressive soils in the natural control of plant-parasitic nematodes, paying particular attention to the role of fungal and bacterial agents of biological control, and with comments on invertebrate nematophages (arthropods, turbullarians, tardigrades, protozoa, annelids and other nematodes). Means of manipulating natural enemies of phytonematodes are discussed, including the opportunities for introducing exotic antagonists into soil. -P.J.Jarvis