Terrestrial, aquatic, and amphibious mollusks from Pacific islands were tested for susceptibility to infection with Angiostrongylus cantonensis. The terrestrial mollusks included five introduced species that occur commonly on high islands and 11 species typical of coral atolls. The aquatic and amphibious mollusks included species of five families of fresh-water snails, and one species of oyster. The veronicellid slug, Laevicaulus alte, was found to be a highly susceptible intermediate host of A. cantonensis, whereas two small subulinid snails, Subulina octona and Prosopeas javanicum, and a helicid snail, Bradybaena similaris, were relatively resistant. The limacid slug, Deroceras laeve, was of intermediate susceptibility when compared with the veronicellid and the snails. As a group, the atoll species were relatively resistant to A. cantonensis. With the exception of Biomphalaria glabrata, a laboratory-cultured aquatic snail not indigenous to the Pacific, the fresh-water snails were either completely or partially resistant. Attempts to infect one species of oyster were unsuccessful.