In this paper a decentralized Model Predictive Controller (MPC) is proposed to load-frequency control in deregulated power systems under harsh conditions such as loss of power generation or loss of controllers in some control areas. To nullify these effects on frequency deviations, the MPC controller uses feed-forward control strategy in each area. The performance of the proposed controller is validated in different scenarios on a multi-area power system. Comparing simulation results with recent proposed robust LMI based PI control strategy, it can be seen that the decentralized MPC scheme effectively regulates frequency without using any emergency control strategy even in severe conditions.