Abstract: Background: Mast cells have been studied for decades due to their prominent role in normal homeostasis and various pathologies. They display a diversity of roles and are proposed to be a part in the pathogenesis of various pathologic lesions. Aims and Objectives: To histologically evaluate the number of mast cells in tissue sections of oral inflammatory lesions, potentially malignant disorders and oral carcinomas. Methodology: 10 cases each of inflammatory lesions, potentially malignant disorders and carcinomas were considered. Tissue sections were stained with H&E to confirm the diagnosis & 1% toluidine blue for evaluation of mast cells. Cells were counted manually in a stepladder fashion and were expressed as an average number of mast cells per 30 high power fields. Results: Inflammatory hyperplasia among the inflammatory lesions and lichen planus among the potentially malignant disorders showed an increase in number of mast cells. While oral Squamous cell carcinoma showed an average of 48 cells/ 30 high power fields. Conclusion: These results suggest that there is significant evidence on the presence and increase in the number of mast cells supporting the biologic effect these cells have on the individual lesions.