We examined the distribution of manganese in rat liver, ileum and brain tissues after chronic administration (50 days) of high-dose MnCl 2 and investigated spectrophotometrically the interactions between manganese and some other trace metals (iron, copper, zinc) levels. In the experimental group (n = 10), MnCl 2 (30 mg/kg/day) was injected for 50 days intraperitoneally. Plasma, erythrocyte, brain, liver and ileum manganese levels were found elevated compared to control group (n = 10). Brain iron levels did not change whereas liver and ileum iron levels increased significantly. Moreover, brain copper and zinc levels did not change, but liver copper and zinc levels were found elevated. Ileum copper levels also increased, but ileum zinc levels did not change compared to control group. The significant increase in erythrocyte manganese content may be due to mitochondrial MnSOD in red blood cells. This situation might have helped to potantiate the antioxidant defense system of organism against free oxygen radicals produced by Mn-induced oxidation reaction.