Abstract: Eight month old Rainbow trout were found dead ten days after shot down of a fresh water recirculation system. The cause of death was diagnosed as chlorine toxicity. The fish carcasses appeared pale and anemic and had enlarged gall bladders and mild multifocal dermatitis. Histopathological inspection revealed edema and foamy vaculation in the gill epithelium, tubular degeneration and presence of golden pigments and azurophilic bodies within phagocytic cells in the kidney, cytoplasmic vacuolation and hyaline droplets in the hepatocytes, mild epithelial erosion and lecuocyte infiltration in the skin and marked erythrophagocytosis in the spleen.