The transition of important parasitic diseases in Korea is briefly reviewed in this article. Soil-transmitted helminthiases, such as ascariasis, trichuriasis, and hookworm infections, which had been prevalent all over the country, decreased remarkably, largely owing to the national control activities by means of mass examination-mass treatment schemes for school students. Paragonimiasis has shown significant reduction in its incidence, but clonorchiasis still remains as an important health-threatening trematode infection. Intestinal trematodiases, including metagonimiasis, heterophyidiases, and echinostomiases are prevalent, and new species, such as Gymonphalloides seoi and Neodiplostomum seoulense, have been documented as new human parasitic diseases. Tapeworm infections including larval cestodiases are also decreasing. Among the protozoan infections, amebiasis and malaria showed an apparent decreasing trend, but in recent years, vivax malaria has become a re-emerging disease. Brugian filariasis, which was prevalent in southern parts of the Korean peninsula, has been completely eliminated nowadays. In terms of the prevalence and distribution, clonorchiasis, enterobiasis, and vivax malaria are currently the major parasitoses of public health importance in Korea.