Background: Cancer stem cells (CSCs) are cancer cells that possess characteristics associated with normal stem cells, specifically the ability to give rise to all cell types found in a particular cancer sample. Such cells are proposed to persist in tumors as a distinct population and cause relapse and metastasis by giving rise to new tumors. Therefore, development of specific therapies targeted at CSCs holds hope for improvement of survival and quality of life of cancer patients. CD133 was reported as a putative marker for identification of CSC in different tumors. However, no studies investigated the presence of CSCs in mucoepidermoid carcinoma (MEC).Materials and Methods: The presence of CSCs in paraffin embedded tissue sections of twelve MEC cases (6 low grade and 6 high grade) was investigated by the expression of CD133 immunohistochemically. Identification and counting of CD133 positive colonies of cells was done using a light microscope. Welixon test was used to detect the statistical significance and to compare CD133 positivity between low grade and high grade MEC.Results: Low grade MEC showed moderate and many CD133 + colonies of cells. Whereas high grade cases showed negative, few and moderate CD133+ cells.Conclusion: The current detection of CD133+ colonies in MEC suggests that MEC follows CSCs model, the CSCs count decrease with increasing the grade of the carcinoma. Therefore, these cells may play a role in tumor initiation. Additionally CD133 is a potential cancer stem cell marker in MEC.