Statement of Problem: Mucoepidermoid carcinoma (MEC) is one of the most common malignancies of the salivary glands. Since the microscopic grading of this tumor is one of the important factors for determining the treatment plan and prognosis, it should have standard and applicable criteria. The AgNORs method is able to determine grading, prognosis and power of proliferation of tumors and can be applied for Mucoepidermoid carcinoma grading.Purpose: The aim of this study was to assess cellular proliferation in salivary glands mucoepidermoid carcinoma with quantitative comparison of AgNORs and its relation to histological grading.Materials and Method: In this descriptive-analytical study, 42 formalin fixed paraffin embedded blocks of mucoepidermoid carcinoma were selected. Five cases were eliminated due to the exclusion criteria and 37 cases including 15 low grades MEC, 11 intermediate grade MEC, and 11 high grade MEC were studied. After AgNORs processing, NORs were counted by light microscope in magnification 1000. The data were analyzed statistically using ANOVA test.Results: Mean AgNORs count for high, intermediate and low grade MEC was 1.65±0.73, 1.1±0.35, and 0.76±0.32, respectively. There was a significant difference in AgNORs count among the three groups ( p <0/05).Conclusion: The findings of this study indicated that this method can be used for microscopic grading of MEC as an accessory method .Future studies are recommended to determine sensitivity and specifity of this method.Key words: Mucoepidermoid carcinoma, AgNORs, Microscopic grading