Cichlid fish, Etroplus maculatus was used in the present study in order to evaluate the median lethal concentration of bisphenol A. Seven different concentrations of bisphenol A at 4 mg, 6 mg, 7 mg, 8 mg, 10 mg, 12 mg and 15 mg/ L for 10 animals per group were exposed for 96 h maintaining a control group. Physico-chemical parameters of water as pH, hardness, dissolved oxygen, and temperature was maintained during the treatment period. LC50 was then determined by probit analysis and it was found to be 6.48 mg/ L concentration. Body weight of all treated groups remained unchanged throughout the experiments as compared with the control animal. However, mucous deposition was significantly increased in bisphenol A-treated groups at all concentrations. Bisphenol A treatment altered normal architecture of liver and gill as revealed by irregular or enucleated hepatic cells and degenerated gill epithelium above 6 mg/ L concentrations. Bisphenol A showed altered behavioural changes as erratic activity followed by restricted movements, haemorrhagic on entire body surface, reddening of fins and finally loss of equilibrium. The study disclose that 96 h LC50 value of bisphenol A is 6.48 mg/ L and the changes in normal behavioural pattern and histopathology of gill and liver demonstrates the acute toxicity of the compound on Etroplus maculatus.