In discussing intestinal helminthiases it is important to appreciate that these constitute only one aspect of parasitic diseases or infections of major pathogenic or social importance which present a significant problem in a high proportion of the world population. Among these, one would include protozoal diseases such as malaria, amoebiasis, African and South American trypanosomiasis and trichomoniasis. Helminthic diseases of greatest importance include schistosomiasis, filariasis and the commonly concurrent intestinal infections arising are ancylostomiasis, ascariasis and trichuriasis. Oxyuriasis is very widespread and although of comparatively trivial pathogenic potential, may be classed as an infection of social significance. Although tapeworm infections are of comparatively low prevalence, they too can have local significance. Added to these, may be hydatid disease and toxocariasis as zoonoses of importance and both without adequate means of treatment.