The objectives of this research were to assess genotype environment interaction and determine stable oat (Avena sativa L.) cultivars for grain yield in Central Anatolian Region of Turkey. Stability analysis [9] were to performed on results for grain yield of 5 oat cultivars (Chekota, Yesilkoy-1779, Yesilkoy-330, Faikbey-2004, Seydisehir-2004) from 24 trials (6 irrigated, 18 rain fed ) was conducted over 6 years in the Central Anatolian Region, Turkey. There was considerable variation in grain yield within and across environments. Year by location and location variability were dominant sources of interactions. The cultivar, “Seydisehir-2004” with respective regression coefficient value of 1.03, the smallest deviations from regressions (S2di) value and the highest grain yield could be considered the most widely adapted cultivar. The other test cultivars were sensitive to production-limiting factors, their wider adaptability, stability and general performance to the fluctuating growing conditions within and across environments being lowered.