Acrylamide is a monomer widely used as an intermediate in the production of one of the organic chemicals, polyacrylamides. The present study was focused to determine the neurotoxic effect of acrylamide on the brain tissue of the fish Oreochromis niloticus. Sublethal concentration i.e., 8.96 µg/L of acrylamide was exposed to fish for 24, 48, 72 and 96 h maintaining control group. The weight of the animal and brain tissue remained unchanged after acrylamide exposure. The activities of superoxide dismutase, catalase and glutathione reductase showed significant (P<0.05) decrease than the control group. However, the levels of lipid peroxidation and hydrogen peroxide generation showed significant (P<0.05) increase in all treatment groups in time-dependent manner. The results suggest the generation of free radicals in brain tissue as a result of acrylamide exposure. The neurotransmitter enzyme, acetylcholinesterase, showed significant (P<0.05) reduction in the brain and serum of blood and this could prove the neurotoxicity of acrylamide. Histological damages like atrophy, infiltration, degeneration, and vacuolization in brain tissue were also observed thereby suggesting acute neurotoxic effect of acrylamide in the fish, Oreochromis niloticus.