Pratylenchus is a genus of nematodes known commonly as lesion nematodes. They are parasitic on plants and are responsible for root lesion disease on many taxa of host plants in temperate regions around the world. Lesion nematodes are migratory endoparasites that feed and reproduce in the root and move around, unlike the cyst or root-knot nematodes, which may stay in one place. They usually only feed on the cortex of the root. Species are distinguished primarily by the morphology of the stylets.

The nematodes, roundworms or eelworms constitute the phylum Nematoda. They are a diverse animal phylum inhabiting a broad range of environments. Most species are free-living, feeding on microorganisms, but there are many that are parasitic. The parasitic worms (helminths) are the cause of soil-transmitted helminthiases.