This research was carried out during the 2016-2017 and 2017-2018 growing seasons at Edirne, Kırklareli, and Tekirdağ locations with the aim of determining some agricultural and quality characteristics of nine registered oat cultivars. According to the results of the examined characteristics, plant height ranged from 101.5 to 132.4 cm, vegetative period from 125.1 to 138.9 days, thousand kernel weight from 26.6 to 40.0 g, test weight from 46.2 to 53.2 kg/hl, protein content from 12.5% to 15.1%, and grain yield from 401.1 to 532.1 kg/da. According to the biplot analysis, PC1 and PC2 (accounting for 69.3% and 18.3% of the total variation, respectively) constituted 87.6% of the total variation. The angle value between the vectors of grain yield and protein content, thousand kernel weight, and test weight was narrow, indicating a high positive relationship between these characteristics, whereas the angle between the vectors of grain yield and plant height and vegetative period was wide, indicating a negative relationship between these characteristics. According to the correlation analysis, grain yield had a positive and significant relationship with test weight (r=0.594**), protein content (r=0.431**), and thousand kernel weight (r=0.350**), and a negative and significant relationship with vegetative period (r=-0.360**) and plant height (r=-0.047**). The highest grain yield was obtained from the cultivars Somun Yıldızı, Kahraman and Kehlibar.