Abstract Bacterial populations from organs (viz., liver, spleen, kidney and gill) of Labeo rohita of the sewage fed fish farm at Kalajharia, Asansol, West Bengal, India, were enumerated, followed by determination of resistance for antibiotics and heavy metals. The total viable counts of bacteria in these organs, observed, were 5.62 x 104, 4.12 x 104, 2.30 x 104 and 1.76 x 104 colony-forming units/mL, respectively. The random bacterial isolates from these fish organs showed resistance in decreasing order for ampicillin (95%), tetracylin (75%), amoxycillin (70%), amikacin (65%), chloramphenicol (50%), sparfloxacin (40%), gentamycin (30%), levofloxacin (25%), streptomycin (10%), and ciprofloxacin (05%). Most of the isolates exhibited an increasing order of tolerance for the metals (μg/mL) copper (200), cadmium (200), iron (400) and chromium (400), with minimum inhibitory concentration (MIC) ranging from <50 to 1600 μg/mL. A total of 40 bacteria have been successfully isolated from internal organs of Labeo rohita (8 isolates of Aeromonas spp., 21 of Edwardsiella spp., 6 of Flavobacterium spp. and 5 of Vibrio spp.). In terms of antibiotic susceptibility testing, each isolate was tested against 21 antibiotics, resulting in 482 (57.3%) cases of sensitivity and 61 (7.3%) cases of partial sensitivity. Meanwhile, 297 (35.4%) bacterial isolates were registered as resistant. The multiple antibiotic resistance (MAR) index of each bacterial species indicated that bacteria from raised bullfrogs have been exposed to tested antibiotics with results ranging from 0.27 to 0.39. These observations indicate that the significant occurrence of bacterial population in organs of fish with high incidence of resistance for antibiotics and heavy metals may pose risk to fish fauna and public health.