A new minute intestinal fluke, recovered from a Korean woman suffering from acute pancreatitis and gastrointestinal difficulties, was described as Gymnophalloides seoi. The coastal village where the patient resided was found to be a highly endemic area for this fluke, and 24 other endemic areas have been found. This fluke infection is now recognized as an emerging parasitic disease. Its second intermediate host is the oyster, and migrating birds are a natural definitive host. This new trematode might exist in other countries.