Interest in the relatively new field of medical malacology was arounsed especially during the last war when a number of American soldiers contracted Oriental blood fluke (Schistosoma japonicum) during General MacArthur’s campaign in Leyte. The need for studying the mollusk intermediate hosts of a number of snail-borne diseases then began to receive somewhat the attention accorded insects involved in vector roles in the sister field of medical entomology. While the process of obtaining support has been slow, more and more basic studies are being initiated to understand better the roles of snails in relation to human and domestic animal diseases. This study is one with many fascinating aspects; it also presents challenging problems, which are far-reaching in the manner in which they concern human health, economics, and the general welfare of many rural communities. While it would be interesting and quite impressive to show some of the intricate interrelations among fields, using schistosomiasis (human blood fluke disease) as an example, it will be just as worth while to consider here another snail-borne disease affecting humans, fasciolopsiasis. Included would be a review of the life cycle of the worm parasite in its relation to its snail host, the role of the snail host in limiting the range of disease infestation, the immediate need for better knowledge of the natural history of the snail hosts, and a brief consideration of some of the difficulties experienced in training personnel to assist in alleviating suffering brought about by this or similar diseases.