Grain exports from Russia, Ukraine and Kazakhstan (RUK) help to improve global grain availability and, hence, food security. However, during the past 15 years, the availability of grain exports from the RUK countries has displayed high variability and has been repeatedly diminished by severe harvest failures. This chapter presents an outlook for RUK grain production and exports up to 2024, taking into account yield variability and possible harvest failures and their impact on national and international food security. For the analysis we use the stochastic version of the AGLINK-COSIMO model. Simulation results show that grain yields in RUK are a major source of uncertainty for international grain markets, especially as regards wheat. In particular by indicating substantial increases in world market prices owing to limited grain exports from RUK, the results highlight the importance of RUK’s grain production for world markets and global food security.