This study was conducted to detect and identify Staphylococcus aureus, Vibrio parahaemolyticus, and Salmonella enterica subsp. using simultaneous multiplex polymerase chain reaction (multiplex PCR) assay. 23S rRNA partial gene (S. aureus), tox R gene (V. parahaemolyticus), and inv A gene (S. enterica subsp.) as diagnostic marker gene were suggested, and their amplicon sizes were 482 bp, 368 bp, and 284 bp, respectively. Non specific amplicons by STA-5F/STA-5R primer, ToxR-F/ToxR-R primer, and 139/141 primer were not observed in genomic DNA of pathogen bacteria as Bacillus cereus, Listeria monocytogenes, Escherichia coli, Proteus vulgaris, Streptococcus pyogenes, Candida albicans, and Shigella sonnei. The extracted crude DNA of targeted bacteria was detected as PCR template successfully. The detection limits were 105~104 CFU/mL and 10 pg of purified genomic DNA of S. aureus, V. parahaemolyticus, and S. enterica subsp. by using simultaneous multiplex PCR.