Background and Objectives: The loss of natural teeth causes many problems; one of major problems that are associated with edentulousness is the hypotonicity of muscles of mastication and decreasing the ability of the patient to chew food properly. Treatment of edentulous patients with complete denture will increase the muscle tonicity and chewing activity. The purpose of this study is to clinically compare patient's chewing ability between lingualized occlusion complete denture and bilaterally balanced occlusion complete dentures. Materials and methods: Two sets of complete dentures with different occlusions were fabricated for ten patients. The patients received bilaterally balanced occlusion (BBO) complete denture and lingualized occlusion (LO) complete denture in random order. The patients wear each set of complete denture for one month. During this month, chewing activity tests were performed for the patients in four different time intervals. The results of these tests were analyzed using t-test and paired t-test to compare between the lingualized occlusion and bilaterally balanced occlusion complete denture and also to compare the results of each time interval with each other. Results: The mean amount of the walnuts that passed through the sieve in LO dentures were (1.78g), during the fourth visit while it was (1.18g) in BBO. There were statistically significant difference between LO and BBO schemes of complete denture when measuring the amount of the chewed walnuts that passed through the sieve in second, third and fourth visit (p=0.037, 0.001 and 0.000). Conclusion: Within the limitations of this study, it has beenconcluded that the chewing ability was higher in patients who were provided with complete dentures fabricated with the LO scheme as compared to those patients who received complete dentures made with BBO scheme. This was due to the fact that LO technique resulted in functionally better complete dentures as compared to the ones made by BBO technique