Vibrio vulnificus is an organism capable of causing septicemia and wound infection in compromised patients. The source of infection is known to be raw oysters and others. The prevalence of the organism in Korean sea water and shellfish is not known. The authors surveyed shellfish and other specimens obtained mainly from a market in Seoul and from ones in Inchon. Five cultures of V. vulnificus were isolated from oyster and clam samples. Two isolates had typical characteristics of the strains isolated from patients, i.e., definite hemolysis and typical biochemical reactions. However, other 2 isolates were sucrose positive, although the identity were confirmed by Center for Disease Control. We do not know wether such strains are pathogenic or not. For the isolation of V. vulnificus from environmental samples, TCBS agar and VV agar were not very selective or differential. We isolated our strains with the use of OF-lactose agar and SPS agar. However OF-lactose agar did not support good growth of V. vulnificus, while SPS agar did not suppress other vibrios.