Due mainly to overharvesting, the world's natural stocks of giant clams have been seriously depleted and most species are now listed as endangered species under CITES (The Convention on International Trade in Endangered Species). There is a perceived shortage of clam supplies in the Pacific Islands and in Chinese areas such as Taiwan and Hong Kong. The development of techniques for the aquaculture (mariculture) of giant clams however raises the possibility of a new source of supply. In this paper, the type of clam products that are likely to be in demand are discussed, elements that may influence these demands are identified and factors that are likely to determine supplies are highlighted. It is anticipated that future ACIAR supported research will enable the economic prospects and possible industry pattern of development of Pacific giant clam mariculture to be pinpointed more precisely.