Synopsis Enormity of crop damage resulting from nematode invasion and the development and the necessity of their effective control under field conditions have come about slowly since past several decades, only after the discovery of some very effective nematicidal chemicals during the 1940s and 1950s, that growers were paying yearly taxes to these tiny but mighty pests. Our crops have been plagued with nematodes since remote past, though unnoticed by early farmers. For centuries these microscopic organisms that feed mainly on the roots have caused pandemic to man's essential crop plants. These deleterious effects on plant growth resulted in reduced yield and poor quality of such crops. Besides they have pivotal role as initiator, cooperators, aggravators and synergists for many other diseases of plants.The natural resistance of wild type has been lost in many cases. Extensive use of pesticides, that sometimes accumulate in the soil and ground water, not only created ecological problems but has led to the increase in pest resistance to these chemicals. These and other problems have generated interest amongst the scientists to explore alternative approaches for combating with these notorious organisms. Highly effective methods of nematode control should be evolved with minimum use of chemicals per unit area. The prohibitive costs and the associated hazards in the use of nemoticides lay special emphasis on evolving more remunerative and curative methods in infected crops and prophylactic methods for application in infested soils. The present book incorporates 50 chapters on biological control of plant parasitic nematodes each one contributed by well recognised authorities.