Objectives: To evaluate the mutagenicity of lithium carbonate, a bacterial reverse mutation(Ames) test was carried out using four strains of S. typhimurium(TA1535; TA1537; TA98; and TA100) and one strain of E. coli(WP2uvrA). Materials: This was carried out in a dose range from 312.5 to $5,000{mu}g/plate$ in triplicate with and without S9 activation, which is the most commonly used metabolic activation system supplemented by a post-mitochondrial fraction prepared from the livers of rodents treated with enzyme-inducing agents such as Aroclor 1254 or a combination of phenobarbitone and ${eta}$-naphthoflavone. Results: No significant increases in the number of revertants were observed under the conditions examined in this study. Conclusions: Based on the above observations, it can be concluded that lithium carbonate has no mutagenic activity. Despite the results, it can have an effect by inducing acute oral toxicity, eye irritation and acute aquatic toxicity. Based on this study, we suggest that future studies should be directed toward chronic, carcinogenic testing and other related areas.