Liver flukeis a collective name of apolyphyleticgroup of parasitictrematodesunder the phylumPlatyhelminthes.They are principally parasites of theliverof variousmammals, including humans. Capable of moving along the blood circulation, they can occur also inbile ducts,gallbladder, and liverparenchyma. In these organs, they produce pathological lesions leading to parasitic diseases.