Helminths are long-lived multicellular organisms that have co-evolved with humans over many thousands of years. They are responsible for infections which affect around one third of the human population, at global level. Despite the huge efforts in research during the last years, effective control of helminth infections is still far from optimal standards and the resulting diseases remain neglected. This book aims to give an up-date overview to the epidemiology (including molecular typing), specific biological, immunological and immunopathological aspects, diagnosis and perspectives of control of the most common helminth infections.