The study deals with the impacts of sub-lethal exposure of brick kiln effluent on the activity of lipid and protein peroxide (LPO and PPO), some xenobiotic stress marker enzymes namely Glutathione-s-transferase (GST) and Cytochrome P-450 (CYP), transaminase enzymes namely Aspartate transaminase (AST) and Alanine Aminotransferase (ALT), Alkaline Phosphatase (ALP) and concentration of nitrogenous wastes namely urea and ammonia in the serum with reference to histoarchitecture of gills, hepatopancreas and kidneys of Channa punctata Bloch. Healthy adult fishes of both the sexes were reared in three separated aquaria after acclimatization. After determination of LC50 for 28 days which was found to be 5.5 ± 0.11 ppm, the fishes were reared in three aquaria with aquarium I comprising of normal-control fishes and aquarium II and aquarium III comprising of fishes reared at two sub-lethal concentrations of effluents i.e. 2ppm and 3ppm of effluents. Elevation in the activity of LPO and PPO depicts the oxidative stress upon the organism, and the xenobiotic stress upon the organism was clearly depicted by the increased concentration of GST and CYP. The decreased concentrations of AST, ALT and ALP in the organs with augmentations in the serum depicted the draining of these metabolic enzymes from the organs to the serum due to environmental stress. The stress upon the kidneys was clearly showed by the increased levels of urea and ammonia in the serum. All these anomalies described the stress upon the organism which was evidenced by histological changes in the organs like curving and fusion of gill lamellae, necrosis and vacuolations of hepatopancreatic and kidney tissues.