We report the recovery of 11 taxa of nonmarine mollusks from archaeological sites on Majuro, Maloelap, and Ebon Atolls, Republic of the Marshall Islands. Pupina complanata (Pupinidae), Omphalotropis fragilis (Assimineidae), Truncatella guerinii (Truncatellidae), Lamellidea pusilla and Pacificella variabilis (Achatinellidae), Gastrocopta pediculus (Gastrocoptidae), Nesopupa sp. (Vertiginidae), “Succinea” sp. (Succineidae), Allopeas gracile (Subulinidae), and Liardetia samoensis (Helicarionidae) arrived in these islands prehistorically; Liardetia sculpta (Helicarionidae) has not yet been recovered from levels of confirmed prehistoric age. Pupina complanata, O. fragilis, and probably also Nesopupa sp., and "Succinea” sp. are Micronesian endemics. Al other species are widely distributed in Micronesia and Polynesia and (except for the strand-line species T. guerinii) were undoubtedly translocated to the Marshall Islands by the prehistoric voyages of Pacific islanders. The precise role of human transport in the dispersal of the Micronesian endemics remains unclear, but because these atolls have been emergent for a mere 3,000 yr or so, human transport is likely in view of the known rarity of natural interarchipelagic dispersal of nonmarine mollusks.