In the study the qualitative and quantitative characteristics of milk obtained from Simmental cows imported from the Czech Republic (n = 63), their daughters born in Poland (n=46), and cows of the Polish Black-and-White breed with up to 50% Holstein-Friesian genes (n = 21) were compared. Actual milk yield, value-corrected milk (VCM) and ener-gy-corrected milk (ECM), as well as fat and protein content in the milk, were compared in 305-day lactation for a one-year period. The udder health of cows was assessed on the basis of the somatic cell count (SCC) in the milk and the log-trans-formed somatic cell count (LnSCC). Polish Black-and-White cows had the highest actual milk yield and fat yield. Simmen-tals from the Czech Republic, on the other hand, had the highest average protein yield and the highest VCM yield. The season and the breed and origin of the cows were found to significantly affect the number of milk samples with an ele-vated SCC. Simmental cows born in Poland had significantly the lowest mean SCC and LnSCC, as compared to both the Czech Simmentals and the Black-and-White breed. The Sim-mental cows, although their milk yield was lower than that of the Black-and-White breed, had better udder health assessed on the basis of LnSCC and their milk had a more favourable protein-to-fat ratio. Simmental cows can be successfully used on farms adjacent to areas under environmental protection, where intensive agricultural production, including livestock farming, is prohibited.