In the two-factors field experiment carried out at Lipnik near Stargard Szczeciński and Strzelce near Kutno, naked oat cultivars (Akt and STH 296) with covered oat Bajka at two nitrogen doses 60 and 100 kg/ha at Lipnik and 70 and 100 kg/ha at Strzelce, were compared. Interaction between cultivars and nitrogen doses was not significant. Increasing nitrogen fertilization caused decrease of grain yield of oats at Lipnik by 1,7 and at Strzelce by 5,4 dt/ha . The naked cultivars yielded lower about 35 and 31 % than cv. Bajka, at Lipnik and Strzelce, respectively. It was caused by lower weight of 1000 grains, lower plant and panicle density.