A total of 300 marine fishes of two different species represented as (150) tilapia Zilli and 150 mugil capito) were freshly collected randomly from the different markets in the Ismailia governorate, during different seasons. The samples were subjected to full clinical, postmortem, and bacteriological studies. The common clinical signs were darkness in the skin, hemorrhage in the base of fins, eyes & different parts of the body, abdominal distention, congestion in gills, and increase in mucous secretion. The postmortem finding showed white serous fluid tinged with blood in the abdominal cavity and pale or congested liver, kidney, and spleen. The result indicated that the prevalence of bacterial pathogens among naturally infected marine fishes were Aeromonas hydrophila 91 isolates (39.39%), V. alginolyticus 67 isolates (29%), P. fluorescens 42 isolates (18.18%), V. fluvialis 17 isolates (7.4%), P.aeruginosa 14 (6.06%). The result of the antibiogram revealed that Aeromonas hydrophila is highly sensitive to ciprofloxacin, while ciprofloxacin and rifampicin are more effective against P. fluorescence, also ciprofloxacin and amikacin against P. aeruginosa, while V. alginolyticus was highly sensitive to oxytetracycline and rifampicin. Ciprofloxacin and naldixic acid more effective against V. fluvialis