The objective of this study was to determine the effect of different production systems on contents of 29 major and trace elements in cow’s hair. The experimental material consisted of 30 cows of Polish Holstein-Friesian (HF) breed, from one dairy organic farm (15 cows) and one dairy conventional farm (15 cows). All the farms were located in one climatic zone and under similar soil conditions. In conventional farm cows were kept in a cubicle barn and cows were fed with total mixed ration (TMR) from a feeding around the year. In organic farms cows were kept in traditional tied-up barns. Feeding was traditional, with ration components offered separately. Cows were grazed from May to October. Depending on pasture yield and availability of other feeds, feeding ration was supplemented by hay, straw, silage and cereals. Samples of hair for analyses of minerals were collected in October, i.e. after pasture feeding. The hair was taken from poll. The concentration of Ca, K, Mg, Na, P, S, B, Ba, Co, Cr, Cu, Fe, Ge, I, Li, Mn, Mo, Ni, Se, Si, Sn, Sr, V, Zn, Al, As, Cd, Hg, Pb was determined. The content of Ca, K, Na, P and S in hair of cows from conventional farm were the similar like in the organic cows. The content of Mg was significantly higher in cows from intensive production system compared to cows from ecological farm with pasture feeding. The significantly lower contents of B, Ba, Cr, Cu, Ge, I, Li, Mn, Mo, Ni, Se, Si, Sn, Sr, V, Zn were shown in organic farm. The content of Al, As in cow’s hair were significantly lower, but content of Cd significantly higher in cows from conventional dairy farm compared to ecological farm. There was no difference in Hg and Pb content. It seems that the wider investigations of mineral composition of cow’s hair could be useful for settlement of reference value for some elements and would make a contribution to better animals’ welfare.