The offered volume intends to review the biological control theme of phytonematodes from several prospects: ecological; applicative as well as commercial state of the art; understanding the mode-of-action of various biocontrol systems; interaction between the plant host, nematodes' surface and microorganism's; candidates for biocontrol; extrapolation of the wide knowledge existed in another systems for understanding biocontrol processes: C. elegans as a model and lessons from other natural systems; and exploiting advanced genomic tools to promote understanding biocontrol processes and thereafter improve specific biological control agents.