Background: Mast cells(MC) are cells of the immune cells which can secrete a variety of molecules. Many studies suggest that mast cells may either promote tumour growth in some types of cancer or may act in an opposite manner in other tumour types. Aim: To evaluate the association of mast cells in the different grades of Oral Squamous Cell Carcinoma(OSCC). Material and methods: Fifteen diagnosed cases each of well, moderate and poorly differentiated OSCC were identified from the institutional archival material. Two slides each were made of 5 μm thickness and stained with Hematoxylin and eosin and 1% Toluidine blue stain. Each section was evaluated for mast cells in peritumoural, intratumoural locations and at the invasive front of the tumour. The results obtained were subjected to statistical evaluation by an SPSS version 19 using Chi square test, Anova and Post hoc Tuckey tests. Results: An inverse relation was observed between MC count with grade of the tumour with maximum MC located in the peritumoural area followed by the invasive front and the least in the intra tumoural areas. Conclusion: The results of the present study suggest that a decrease in MC count is associated with an advanced histologic grade of OSCC and hence a poorer prognosis, thus favouring the protective role of mast cells in OSCC.