The aim of the present study was to assess the effect of iron and copper consumption on weight gain and development of oxidative stress in adipose tissue of rats. Control rats obtained pure drinking water. Iron-treated groups of animals obtained FeSO4•12H2O with drinking water in concentrations of 3 and 6 mg/l, while copper-treated rats obtained CuSO4 in concentrations of 4.88 and 9.76 mg/l. The animals of the 6th group received a mixture of FeSO4•12H2O and CuSO4 in the respective concentrations of 3 and 4.88 mg/l in drinking water. All animals received a standard chow. The final weight of rats from all the experimental groups, especially in those obtaining the combination of iron and cooper, exceeded the control values. Maximal weight of fat pads was observed in animals receiving drinking water with 3 mg/l FeSO4•12H2O, 4.88 and 9.76 mg/l CuSO4, and the mixture of FeSO4•12H2O and CuSO4. The maximal intensity of free radical processes, as estimated by the concentration of fluorescent modified amino acids and the intensity of chemiluminescence in adipose tissue homogenates, was observed in rats obtaining iron in the concentration of 3 mg/l in the drinking water.