Every year, the increase of human population and the accompanying with the growth of industrialization results in the increase of pollution in aquatic ecosystems. Micronucleus (MN) assay is an ideal monitoring system that uses aquatic organisms to assess the genotoxicity of water in the field and in the laboratory. In the present study, an attempt was made to detect the Micronucleus Test (MNT) of Etroplus suratensis in blood erythrocytes after exposure to pyrethroid insecticide lambda-cyhalothrin. The fishes exposed to lambda-cyhalothrin at different sub-lethal concentrations of LC50 value for a short-term exposure. The blood samples obtained from a puncture to the caudal vein using heparinised syringes from control and pesticide treated fishes at 24, 48, 72 and 96 hrs of exposure. From the result, the formation of micronuclei in blood erythrocytes increased from lower to higher concentrations of lambda-cyhalothrin and also the time of exposure were increased. However, the present study revealed that E. suratensis can be used as a good model to study the genotoxic effects of aquatic pollutants in fish.