We analyzed 320 clinical samples of parasitic infections submitted to the Department of Environmental Biology and Medical Parasitology, Hanyang University from January 2004 to June 2011. They consisted of 211 nematode infections, 64 trematode or cestode infections, 32 protozoan infections, and 13 infections with arthropods. The nematode infections included 67 cases of trichuriasis, 62 of anisakiasis (Anisakis sp. and Pseudoterranova decipiens), 40 of enterobiasis, and 24 of ascariasis, as well as other infections including strongyloidiasis, thelaziasis, loiasis, and hookworm infecions. Among the cestode or trematode infections, we observed 27 cases of diphyllobothriasis, 14 of sparganosis, 9 of clonorchiasis, and 5 of paragonimiasis together with a few cases of taeniasis saginata, cysticercosis cellulosae, hymenolepiasis, and echinostomiasis. The protozoan infections included 14 cases of malaria, 4 of cryptosporidiosis, and 3 of trichomoniasis, in addition to infections with Entamoeba histolytica, Entamoeba dispar, Entamoeba coli, Endolimax nana, Giardia lamblia, and Toxoplasma gondii. Among the arthropods, we detected 6 cases of Ixodes sp., 5 of Phthirus pubis, 1 of Sarcoptes scabiei, and 1 of fly larva. The results revealed that trichuriasis, anisakiasis, enterobiasis, and diphyllobothriasis were the most frequently found parasitosis among the clinical samples.