In this paper, master-slave synchronization problem is mainly investigated in the nonlinear dynamical systems. For achieving this end, firstly, both states of the master and slave systems are estimated using a discrete-time extended Kalman filter. Next with a simple control law, the states of the slave system would be synchronized with the master system states. Finally, in order to show the effectiveness of the proposed method, these results are applied to some well-known chaotic problems. Some numerical simulations would be provided to show the efficiency of the proposed approach.