Oat is widely grown in Western Serbia and compared to other cereal crops is reputed to be better suited for production under marginal environments, including low fertility soils and cool wet climates. To determine the effect of cultivar and growing seasons on the yield and components of the oats yield two varieties were examined during three years, in the field experiment of the secondary agricultural-chemical school "Dr Đorđe Radić" in Kraljevo. Trials were arranged according to a randomized scheme in five replications. The following oat traits were analyzed: grain yield, 1000-kernel weight, test weight and plant height. The experiment was performed on extremely acidic pseudogley soil. The obtained results show a high effect of the years on grain yield and certain parameters of its quality. On average, the highest yield of oats 2 .879 t ha-1 was obtained in the variety Vranac. The results of these studies indicate a significant impact of the growing season on grain yield and quality of oats, grown on poor soils of the pseudogley type, which is often present in Western Serbia. Grain yield shows a tendency to increase in years with a higher total amount and better distribution of precipitation during the critical stages of oat plant development.