Introduction: Diabetes adversely affects the morphology of buccal mucosa and may compromise tissue function to favour the occurrence of oral infections and neoplasia. The morphologic and functional changes in oral mucosa can be studied at the cellular level by using exfoliative cytology which can help the diagnosis, with better patient acceptability as it is a painless, non-invasive and less time-consuming procedure. Subjects and Methods: A total of 180 patients were included in the study. Patients were also grouped into the following three categories for further analysis based on their GHb levels: Controlled diabetics (CD) - GHb ≤6%, Uncontrolled diabetics (UCD) - GHb >6% and ≤8% and Non-diabetics (UCD) - GHb >8%. Smears were taken from clinically normal buccal mucosa of these subjects and stained to look for any abnormalities. Results: Statistical analysis of the data obtained showed that the MV of Meisel's cells from non-diabetic patients was significantly higher (p = 0.008) than cells from diabetic subjects. Percentage of micronuclei was significantly higher (p= 0.00) in uncontrolled diabetics as compared to controlled diabetics and non-diabetics. Conclusion: Diabetes Mellitus induces definite morphological and morphometric changes in the exfoliated buccal mucosal cells. However, for establishing exfoliative cytology as a diagnostic tool for diabetes, further studies are required on a larger scale.