Introduction and purpose: Lithium is the treatment of choice in maniac depression psychiatry. In this study, we investigated the possible effects of lithium on the essential trace elements of copper and zinc in brain, liver and kidney of rats. Materials and methods: The control group of rats was fed a normal diet whereas the experimental group received 3 mg Li/kg bw/d for 2 weeks, respectively. After that period, the animals were killed and blood was drawn from their heart, brain, liver and kidney. Tissue lithium, copper and zinc concentrations were measured by atomic absorption spectrophotometer. Results and conclusion: Li in serum increased with the administered dose. Copper serum values were not affected with pharmacologic doses of Li. However, increased serum Li was associated with decreased serum zinc. Pharmacologic doses of Li increased Li content in the liver and Cu content of the brain, and showed no effect in liver and kidney. Pharmacologic dose of Li increased Zn content in liver and kidney but did not affect Zn in the brain. Li therapy may induce major changes in the storage of Cu in the brain and Zn in liver and kidney, respectively.