In this study the effect of single and multiple doses of bismuth on the metabolism andexcretion of endogenous metals (Cu,Zn) was investigated.Wistar rats were administered bismuth chloride subcutaneously (1×3mg Bi/kg or 7×3mgBi/kg).Rats were sacrificed at different time periods after bismuth injections.The leve1s of Cuand Zn were determined in the liver,kidneys and brain,as well as the concentrations ofmetallothionein (MT) in the liver and kidneys.Cu,Zn and total protein levels in the urine ofcontrol and exposed animals were estimated.Additionally,a histopathological examinationof the kidneys and brain was carried out. The increase in the renal and hepatic Cu and Zn content was paralleled by anaugmentation in the level of MT in these organs following both kinds of exposure to bismuth.Some changes in the ultrastructure of the kidneys were correlated with the dose of bismuth.Zinc content in the brains of exposed rats was lower than in control animals brains,but therewas no difference in copper level and Wistar rats were administered bismuth chloride subcutaneously (1 × 3 mg Bi / kg or 7 × 3 mg Bi / kg). Rats were sacrificed at different time periods after bismuth injections. The leve1s of Cuand Zn were determined in the liver, kidneys and brain, as well as the concentrations ofmetallothionein (MT) in the liver and kidneys. Cu, Zn and total protein levels in the urine of control and exposed animals were estimated. Additionally, a histopathological examination of the kidneys and brain was carried out. The increase in the renal and hepatic Cu and Zn content was paralleled by anaugmentation in the level of MT in these organs both both of exposure to bismuth .Some changes in the ultrastructure of the kidneys were correlated with the dose of bismuth. Zinc content in the brains of exposed rats was lower than in control animals brains, but therewas no difference i n copper level and