The aim of the study was to determine the content of macro- and microelements in the blood serum and in the longissimus dorsi muscle (Musculus longissimus dorsi – Mld) of lambs, dependent on the system of maintenance of the lambs with their mothers, the genotype and the year of research. Lambs were reared together with their mothers in two maintenance systems: indoor system in a sheep fold and outdoor system in the open air with unlimited access to pasture. The lambs were of two genotypes: PLS (Polish Lowland sheep Uhruska variety) and BCP (the synthetic prolific meat line sheep). The concentration of elements in the blood serum was estimated in the second and third month of life, as well as in the Mld, after slaughter of the lambs at a weight of 25-28 kg. The results of the study show that the mineral compositions of blood change with the lamb’s age and related method of feeding. The system of maintenance had a modifying effect on the calcium, copper and zinc content in the blood serum, especially in the third month of the lambs’ life. It was noted that the copper content in the longissimus dorsi muscle in the lambs kept with their mothers in the outdoor system was higher compared to the lambs kept indoors. A similar tendency was observed in the content of mineral elements in the blood serum and in the longissimus dorsi muscle, dependent on the genotype and maintenance system. The concentration of elements (except sodium) in the blood serum in the lambs comprised within the reference values set for adult sheep.