Copper is an essential trace element that is vital to the health of all living things (humans, plants, animals, and microorganisms). Copper ions are quite toxic to fish when concentrations are increased in environmental exposures often resulting in physiological, histological, biochemical and enzymatic alterations in fish, which have a great potential to serve as biomarkers. Pseudomonas putida has the unique ability to transform a toxic pollutant into a biodegradable product. The objective of this study was to examine the copper toxicity in Catla Catla, and the efficiency of Pseudomonas putida on copper biodegradation was assessed by biochemical parameters such as total protein, carbohydrate, phosphatase, protease, lipase, transaminases, lipid peroxidation, reduced glutathione and copper content and histopathology of muscle tissues of Catla Catla. To conclude that Pseudomonas putida effectively reduced the copper toxicity on Catla Catla.