Fasciola gigantica is the liver fluke that affects cattle — and can be transmitted to humans — the tropical counterpart of Fasciola hepatica. This large flatworm lives in the bile ducts of ruminants, its eggs passing in faeces to hatch in water, develop in snails, and encyst on aquatic vegetation as metacercariae. Cattle and people are infected by eating contaminated water plants — watercress is the classic vehicle — whereupon the juvenile flukes migrate through the liver to the bile ducts, causing inflammation, fibrosis, and in heavy infections, serious liver damage. Human fascioliasis from F. gigantica concentrates in tropical Africa and Asia, where it is a neglected but significant foodborne parasitosis. Control means managing snail habitats, treating livestock, and washing or cooking aquatic vegetables.