Although there are thousands of parasites all over the world, Schistosoma spp. are unique in terms of their morphology. Although they have separate bodies as “male” and “female,” they live in such a way that the female resides within the male. Schistosoma spp., classified in the family of trematodes, has about twenty members, five of which cause a disease called schistosomiasis (or bilharzia) in humans. This disease causes a variety of symptoms, ranging from simple skin lesions to a dramatic clinical scenario of bladder carcinoma. Although there are many different diagnostic and therapeutic methods, schistosomiasis is still an important threat to humans and a significant challenge for healthcare professionals. This book discusses the morphology, geographic distribution, and evolution of Schistosoma spp., as well as the diagnosis, treatment, and prevention of schistosomiasis.