The book describes the basic aspects of nematology, viz., Methodology, Morphology, Systematics and Classification, Biology, Physiology and Ecology. It is designed and written in an explicit manner so that undergraduate students without a nematology background can easily perceive basics of the discipline, and at the same time postgraduate students can get in-depth and up-to-date information on various fundamental and advanced aspects of nematology. The book contains around 80 schematic and natural diagrams.