Aims To develop an effective multiplex polymerase chain reaction (PCR) for the simultaneous detection of three important Vibrio species, Vibrio cholerae (Vc), V. parahaemolyticus (Vp) and V. vulnificus (Vv) using the groEL gene, a potential phylogenetic marker. Methods and Results Three species-specific primer sets were designed to target Vc, Vp and Vv. A total of 131 Vibrio and non-Vibrio strains were used to determine the specificity and sensitivity of primers. The primers produced specific PCR fragments from all target species strains and did not cross-react with other Vibrio and non-Vibrio species. This PCR method showed good efficiency in detecting coexisting target species in the same sample with a detection limit of 100 pg of Vc, Vp and Vv from mixed purified DNA. Detection of three target species was also possible from artificially inoculated shellfish, flounder and sea water. Conclusions The groEL gene is a potential marker for accurate simultaneous detection of Vc, Vp and Vv and could be used to detect these species in environmental and clinical samples. Significance and Impact of the Study This newly developed multiplex PCR is a useful and cost-effective method that is applicable in a disease-outbreak prediction system and may provide an effective tool for both the epidemiologist and ecologist.