This study was conducted to define grain yield and quality traits of local oat cultivars and to assess the adaptability to and stability of cultivars in different environments of Central and West Black Sea Region of Turkey. Twenty-five oat genotypes were evaluated in a randomized block design with four replications in six different environments. Genotype, environment and genotype x environment interaction had highly significant effects on grain yield and quality traits. The oat genotypes exhibited significant variations in grain yield (2.15-5.81 t ha(-1))test weight (40.8-46.7 kg), thousand-grain weight (21.8-34.2g), groat percentage (70.1-73.6 %), protein (12.0- 13.3%), ash (2.34-2.77%), starch (42.7-49.6 %), beta-glucan (2.93-3.56%), ADF (13.6-16.4%), NDF (31.5-34.4 %) and fat (5.69-6.80). The genotypes G5, G7, G12, G15, and G17 were identified as the most stable cultivars for grain yield. These genotypes also had high values for desired quality traits. Therefore, these genotypes can be recommended for tested environments and similar environments. It was concluded that the genotypes with high values for desired quality traits could be used in further oat breeding programs to improve new cultivars with stable grain yield and high quality.