The aim of present study is to assess the effect of complete denture relining on the electromyogram of masticatory muscles. The electromyography and the computer-EMG system were used for collecting and processing bilateral masseter and anterior temporal muscles activities before and after denture relining. The results showed that the mean myoelectric potentials of the masticatory muscles was increased during chewing and maximal biting when the dentures were relined. The conclusion was that the level of the masticatory muscle activity was increased when a clinically acceptable occlusal vertical dimension was obtained by using relining method.