Echinostomes are medically- and veterinary-important parasitic flatworms that invade humans, domestic animals and wildlife and also parasitize in their larval stages numerous invertebrate and cold-blooded vertebrate hosts. The interest in echinostomes in parasitology and general biology comes from several areas: (1) Human infections; (2) Experimental models; (3) Animal infections; (4) Systematics. The application of novel techniques is moving the echinostomes to the frontline of parasitology in fields such as systematics, immunobiology in vertebrate and invertebrate organisms and proteomics among others. The Biology of Echinostomes demonstrates the application of new techniques to a group of trematodes that may serve to obtain information of great value in parasitology