Introduction: Mast cells are mobile granule-containing secretory cells that are distributed preferentially about the microvascular endothelium in oral mucosa. Mast cell synthesis and release of mediators exerts potent immunoregulatory effects on other cell types, while several T-lymphocyte-derived cytokines influence mast cell migration and mediator release in oral leukoplakia which Sis a well known potentially malignant disorder. Aim: To enumerate role played by mast cells and the status of mast cell (Intact or Degranulated) density in mild, moderate and severe cases of epithelial dysplasias which are clinically diagnosed as leukoplakia compared to normal tissue. Materials and Methods: 30 formalin-fixed -paraffin-embedded tissue specimens of epithelial dysplasias (10-mild, 10-moderate, 10-severe cases), distilled water, 1%Toluidine blue, absolute alcohol and Xylene. Mast cells were counted in 4 random high power fields (40x) using eye-piece (10x) fitted with 1cm2 graticule. Results: A significant difference in the average number of Mast cells / 1 HPF at p<=0.005 was observed when compared the averages of Normal, Mild, Moderate and Severe cases. Conclusion: There is an increase in the number of mast cells gradually from mild, moderate to severe dysplasias but there is no significance when we compared mild with moderate dysplasias.