Background: Alkali metals such as lithium nitrate due to its properties have found their application in industries. However, reports of acute toxicological impact of lithium nitrate on aquatic animals are largely not available in the literature. Objective: With this interest, we have assessed the impact of LiNO 3 on Catla catla, a freshwater fish widely consumed. Materials and Methods: In this study, LC 50 of LiNO 3 was determined to be 5ppm, for 24 h. Following this, 1/10 th of the LC 50 levels of LiNO 3 (0.5ppm) was chosen for acute investigation of 96 h. Results: The results demonstrated increase in serum aspartate transaminase (AST), alanine transaminase (ALT) and lactate dehydrogenase (LDH) in treated fish. Further examinations disclosed changes in antioxidant enzyme systems with remarkable changes in the serum catalase (CAT) and superoxide dismutase (SOD) contents, with elevation in malondialdehyde (MDA). The investigation found increased glutamate levels in the brain tissue of treated groups, demonstrating tissue damage. Conclusion: The study underlines the toxicological impact of LiNO 3 and role of certain potential biomarkers which determine the impact of these toxicants in aquatic environment.