Up until now, we have identified 17 exotic species of Mollusca in Korea. These include Achatina (Lissachatina) fulica, Limax flavus, Limax marginatus, Deroceras reticulatum, Hawaiia minuscula, Zonitoides yessoensis, Zonitoides arboreus, Physa acuta, Pomacea canaliculata, Pomacea insularus, Crepidula (Crepidula) onyx, Mytilus galloprovincialis, Xenotrobus securis, Perna viridis, Argopecten irradians irradians, Pinctada fucata, and Pinctada margaritifera. Among them Achatina (Lissachatina) fulica, Pomacea canaliculata, Pomacea insularus, Argopecten irradians irradians, Pinctada fucata, and Pinctada margaritifera were intentionally introduced, whereas remainings were unintentionally introduced into Korean fauna. These foreign species can be divided into three groups on the basis of their habitats: A. fulica, L. flavus, L. marginatus, D. reticulatum, H. minuscula, Z. yessoensis, and Z. arboreus in terrestrial habitat; P. acuta, P. canaliculata, and P. insularus in fresh water; and C. onyx, M. galloprovincialis, L. fortuneikikuchii, P. viridis, A. irradiansirradians, P. fucata, and P. margaritifera in sea water. Taxanomically, 11 species belong to Gastropoda, whereas 6 species are classified to Bivalvia.