The present study was conducted on 250 diseased Nile tilapia (Oreochromis niloticus) fish of various sizes were collected from different fish markets at Kaliobia Governorate, Egypt, during the period from May (2017) to January (2019) for inspection of Aeromonas and Pseudomonas strains. Samples were collected from apparently pathognomic lesions in muscle, liver, kidney, intestine and spleen for bacteriological examination. The results revealed that, 161 Aeromonas and Pseudomonas species; 118 Aeromonas (73.3%) and 43 Pseudomonas species (26.7%) were isolated mostly from 50 muscle lesion samples followed by 41 liver samples then 35 kidney samples ; 32 intestine samples and 3 spleen lesion samples . Aeromonas strains were highly sensitive to meropenem followed by ciprofloxacin; norfloxacin; gentamycin and florphenicol. Meanwhile, they were highly resistant for ampicillin and methicillin followed by oxacillin; penicillin-G; amoxicillin; cefotaxime; oxytetracycline and streptomycin. In addition, Pseudomonas strains were highly sensitive to meropenem followed by gentamycin; norfloxacin; ciprofloxacin and florphenicol. In contrast, they were highly resistant for ampicillin; methicillin and penicillin-G followed by amoxicillin; oxacillin and cefotaxime.