Vibrio alginolyticus was isolated from Mugile seheli collected from private farm in Suez Governorate. Clinically examined fish exhibited dark colouration, erosions and haemorrhages of body parts. The target organs for isolation were kidney (52%), liver (48%) and spleen (15%). Isolates were biochemically and molecularly identified using species specific primers targeting collagenase gene and tdh gene. Investigation revealed that, 17 isolates were identified as V.alginolyticus which detected at 737 bp fragment, and only one positive amplicon for tdh gene that was detected at 373bp fragment. The sequence results of V.alginolyticus isolate showed 99% identity with the reference strain V.alginolyticus reported on Gene Bank with accession number (MG271844). The antibiotic sensitivity test of virulent strain of V. alginolyticus showed that, the bacterium was highly resistant to lincomycin 2µg, streptomycin 10µg, ampicillin10µg, trimethoprim 5µg and ampicillin/ sulbactam combination, and intermediate sensitivity to Naldixic acid 30µg, polymyxin B 300u, erythromycin 15µg, Tobramycin 10µg, ciprofloxacin 5µg, kanamycin 30µg and chloramphenicol 30µg. It was also found that, the bacterium was highly sensitive to imipenem 10µg, Oxolonic acid 2µg, oxytetracyclin 30µg, gentamycin 10µg, gatifloxacin 5µg and piperacillin/ tazobactam combination.