A total of 300 healthy and diseased fish samples representing Tilapia nilotica, Clarias lazera and Mugil cephalus (100 of each) were collected from different fish farms in Kafr El-Sheikh Governorate to evaluate their bacteriological and chemical qualities. The obtained results indicated that the mean values of Aerobic Plale Count (APC). Psychrotrophic and Enterobacteriaceae counts of healthy fish samples were 3 x 10+ 0.12 x10', 1.68x102+0.12x10", 8.0x10P+1.76x102 bacteria per gram of muscle samples, for Tilapia nilotica. On the other hand, in case of Clarias lazera the mean values of the same bacterial groups were 3.03x10°+ 0.44x10", 1.76x10'+0.07x103 and 3.28x102+0.33x102, per gram of muscles. While these mean values were 1.86x10°+0.10x10°, 1.43x102+0.65x10, and 2.70x10+0.10 x 10 bacteria per gram of muscle samples of Mugil cephalus, respectively. In case of diseased fish muscle samples the results in Tilapia nilotica were 6.17x10ʻ+0.32x10°, 4.16x10*+0.14x104 and 4.80x10°+0.22x10", respectively. In Clarias lazera muscle sample the mean values were 6.25x10°+0.21x10°, 3.75x10*+0.21x104 and 6.25x103 + 0.21x10/gram muscle, respectively, while in case of muscle samples from diseased Mugil cephalus the mean values were 2.30x10 +0.12x10, 1.65x10*+0.15x104 and 3.60 x 10+0.19 x 10' per gram muscle sample, respectively. Aeromonas hydrophila, Pseudomonas aeruginosa, Vibrio parahaemolyticus, E. coli, Salmonella spp < /em>., Listeria spp < /em>. Flavobacterium, Achromobacter, Chromobacterium and Yersinia species were isolated from examined samples with different percentages Regardless the condition of the fish the overall mean values of pH and Total Volatile Nitrogen for muscle samples were 7.01+0.018 & 19.6+0.43 mg%, 7.04+0.03 and 6.98+0.016 & 19.78+0.28 mg% and 6.98+0.016 & 23.13+0.12 mg% for Tilapia nilotica, Clarias lazera and Mugil cephalus, respectively. Furthermore, the public health significance of isolated bacteria and some recommendations to ensure consumer safety were discussed.