Plant parasitic nematodes are major pests of agricultural crops and cause huge monetary losses. There is a very high risk of spread from one country to another, with the movement of plants and planting materials e.g. seeds, bulbs, corms, suckers, tubers, rhizomes, rooted plants, nursery stock and cut flowers. In view of the large quantities and the wide variety of materials being imported and exported, it is important to assess the status of invasive nematodes and their quarantine importance in relation to agricultural trade. This book contains information on around 100 invasive nematodes and their potential threat in different countries. Each nematode entry includes information on: authentic identification, geographical distribution, risk of introduction, host ranges, symptoms, biology and ecology, planting material liable to carry the nematode(s) and its vector if any, chance of establishment, likely impact, phytosanitary measures, and a detailed account of diagnosis procedures e.g. sampling, isolation/detection and identification with morphological and molecular characterization. It offers a global perspective on invasive nematodes suitable for practitioners, professionals, scientists, researchers, students, and government officials working in plant quarantine and biosecurity.