Heavy metal contamination have devastating effects on the ecological balance of the recipient environment and a diversity of aquatic organisms. Among animal species, fishes are the inhabitants that cannot escape from the detrimental effect of these pollutants. Fish are widely used to evaluate the health of aquatic ecosystems because pollutants build up in the food chain and are responsible for adverse effects and death in this ecosystem. Pollutants induce mortality, genotoxicity and histopathology thus impairing respiration, metabolism and enzyme activities in affected fishes. Therefore, in the present work the histopathological alterations caused to Anabas testudineus on exposure to aquatic toxicants present in the Buckingham canal, Chennai, Tamil Nadu, India were studied.