This study was conducted to evaluate the level of microbial contamination in three types of chilled fish that are sold in Zagazig markets [grey mullet (Mugil cephalus), Tilapia (Oreochromis niloticus) and African catfish(Clarias gariepinus)]. A total of 150 fish samples belonging to the 3 species (50 of each) were examined for S. aureus,Coliforms, and E. coli. The incidence of S. aureus in examined samples were ( 20%, 28% and 42%)respectively, while the range of S. aureus count in the examined fish samples ranged from 2.39 to 3.52, 3.58 to 4.23, and 3.59 to 4.91log ¹⁰ CFU/g respectively.The coliforms count in examined fish samples ranged from 2.04 to 3.66, 1.47 to 4.04 and 1.56 to 4.04log ¹⁰ CFU/grespectively. The incidence of E. coli in examined samples were (8%, 12% and 22 % ) respectively.Staphylococcal enterotoxin gene (coa) and virulence genes (stx1 and stx2 genes) in E. coli isolates were determined by multiplex PCR. Three isolates of E. coli found to harbor stx2 gene while stx1 could not be detected in all examined isolates. Coa gene was detected in five examined isolates of S. aureus. The present findings concluded that those fish species could constitute a public health hazard. This study highlighted the importance of screening of fish for enterotoxigenic S. aureus strains and STEC isolates, and also assessing the hygienic quality of fish.