Purpose: The aim of the study was to evaluate the effect of two different occlusal plane orientations (Ala tragus line and Retro molar pad) on electromyographic activity of masseter and anterior temporalis muscles and sound production in complete denture wearers. Material and methods: Ten completely edentulous patients' ages ranged from 55-65years. All patients had received two dentures first denture was made according to Ala tragus line (Group І) and second denture was made according to retro molar pad (Group ІІ). Electromyographic activity was evaluated for both groups after one week, one month and three months with one week washing period between the two groups. While Speech analysis was evaluated after one week and one month for both groups. Results: The results of this study showed that no significant differences between both groups regarding to Electromyographic activity and phonetics. Conclusion: Based on the results of this study no single technique seems completely accurate to determine the exact occlusal plane. A combination of different landmarks along with a good clinical assessment should be considered in order to determine the location of the occlusal plane in edentulous patients.