Vibrio vulnificus is a halophilic estuarine bacterium that causes fatal primary septicemia and necrotizing wound infections. The gram negative bacterium was first identified in 1976 and clinical syndromes associated with the organism were described in 1980. In Korea, clinical cases were first reported in 1979 and the bacterium was first isolated in 1982. The primary septicemia occurs following ingestion of raw seafood. V. vulnificus preferentially affects subjects with hepatic diseases, heavy alcohol drinking habit, diabetes mellitus, hemochromatosis, and immunosuppression from corticosteroid therapy, AIDS, and malignancy. The primary septicemia progresses very rapidly and results in high fatality, 50 to 80% in a day or two.