80 naturally infected farmed Mugil Cephalus were collected from a private fish farm at Dakahlia Governorate, revealed clinically congestion and haemorrhages on skin and fins rot. The fish were examined bacteriologically for detection of Vibrio species. The obtained results revealed that 27 (33.75%) were positive for Vibrio species which identified morphologically and biochemically to V. anguillarum biotype C 16 (59.25%), V. ordalii 8(29.62%), V. damsela 5 (18.51%) and V. vulnificus 3(11.11%). The pathogencity of isolated V. anguillarum biotype C strains in Mugil fish revealed high mortality (80%) in experimentally healthy fish. Sensitivity test of the isolated strains showed that Vibrio spp. were sensitive for Enrofloxacin, Colistin sulphate, Nitrofurantoin, Oxytetracycline, Tetracycline and Cefotaxim.