Although Fasciola hepatica (liver fluke, Lewerbot) is essentially a parasite of herbivorous animals, especially sheep and cattle, in which it causes the disease known as 'liver rot', it has been reported in man as an erratic infestation. The recent recognition of 2 human cases, one presenting with massive haemorrhage from the liver into the intestine, and the other with intermittent obstruction of the common bile-duct, prompted an extensive review of the literature, from which it became apparent that fascioliasis is not so very rare in man, in whom it may produce variable clinical pictures. It is the purpose of this paper to draw attention to the pathological effects of infestation by F. hepatica, to discuss the clinical features, diagnosis and treatment of fascioliasis (distomiasis), and to report the 2 cases encountered.