This study was carried out to determine the effects of different sowing times and harvest stages on the yield and forage quality of buckwheat in Marmara's conditions. The experiment was conducted in 2018 and 2019 in Bursa Uludag University Agricultural Application and Research Area using the Gunes variety as plant material. The experiment arranged randomized complete block design with split plot arrangement having three replications. Four different sowing times (15 April, 1 May, 15 May and 1 June) and three different harvest stages (flowering, milky and dough) were considered in the main plot and sub-plot, respectively. Results showed that higher plant height and dry matter yield values were obtained from plants sown on 15 April and harvested during the milky or dough stages. The highest crude protein ratio, crude protein yield and relative feed value, and the lowest acid detergent fiber and neutral detergent fiber values were determined in plants that were sown early and harvested during flowering stage. In general, delaying the harvest stage increased the yield of buckwheat but negatively affected the forage quality.