Distribution of pathogenic vibrios in the seawater of live fish tank and effect of environmental factors an their existence were investigated by collecting samples from fish markets and restaurants in 6 different cities. Pathogenic vibrios and coliforms were determined by using the most probable number (MPN) procedure, and aerobic plate count was enumerated by the standard pour plate method. No Vibrio cholerae O1 was detected in all the samples tested. Detection rates of Y. cholerae non-Ol, V. parahaemolyticus and V. vulnificus in all the samples tested were 7.7%, 69.2% and 23.1%, respectively. Water temperature and turbidity of the seawaber measured were higher in the pathogenic vibrios positive samples than in those negative samples. However, higher salinity and pH were shown in the pathogenic vibrios negative samples than in positive samples. The aerobic plate counts and MPN of total and fecal coliforms in the seawater were higher in the presence of pathogenic vibrios than in the absence of pathogenic vibrios. In this study, the presence of pathogenic vibrios in the seawater tested was closely related with other physiochemical parameters and populations of coliforms, indicators for food safety.