Histopathological alterations can be used as indicators for the effects of various anthropogenic pollutants on organisms and are reflect of overall health of the entire population in the ecosystem. The fingerlings of Cirrhinus mrigala were procured from fish farm and acclimatized in the laboratory for one week. The LC50 value was determined and the experimental fishes was exposed to sublethal concentration. After the exposure periods for 10, 20 and 30 days the fishes were sacrificed and the organs like gill, liver and kidney were examined for histopathological alterations. Degeneration of primary and secondary lamellae in gills, karyolysis, degeneration of hepatocytes, clumping of nucleus in liver and tubular necrosis, shrunken glomerulus in the kidney was observed. From the present study the changes observed in tissues of different organs of fishes were evident to show the effects of aquatic pollution.