Enzymatic antioxidants serve as an important biological defense against oxidative stress. Information on antioxidant defense in fish is meager despite that fish are constantly exposed to environmental stress. Therefore, this study was planned to assess the changes in biochemical and molecular parameters in various tissues of freshwater fish, Ctenopharyngodon idella., in response to long-term exposures to pesticides mixture. Fish were exposed to different sub-lethal concentrations (1/5th of LC50, 1/4th of LC50, 1/3rd of LC50) of pesticides mixture for 60 days. The samples of ifsh blood and organs viz. gills, liver, kidney, brain, muscles and heart were dissected after every 15 days of exposure to assess the catalase activity and DNA damage. Result of this study revealed that exposure of pesticides mixture result of induced significant decrease in catalase activity in all selected organs of test fish with the increase in exposure duration and the mutagenic potential of the pesticides causes maximum DNA damage after 60 days of pesticides mixture exposure. An exposure of 1/3rd of LC50 to C. idella induced significantly higher number of nuclear abnormalities interms of dumble, blebbed and notched shaped nuclei. The variation in biochemical and molecular variation parameters in different organs of test fish samples in comparison with the control shows the adverse effect of pesticides pollution on the fish health.