Materials and Methods: Patient records were retrieved during a 10 year period from 2001 to 2010. Data of all reactive hyperplasias namely focal fibrous hyperplasia, pyogenic granuloma (PG), peripheral ossifying fibroma (POF) and peripheral giant cell granuloma (PGCG) were reviewed and 10 cases seen in the gingiva were selected for each category and stained with 1% toluidine blue for mast cells. Statistical analysis was applied to see the significant differences between the groups and with the normal gingival tissue. One-way ANOVA-F and unpaired t-test was applied and significant differences were seen between the groups at 5% level of significance. 

  Results: In this study, mast cell count was maximum in POF and fibrous hyperplasia (FH) followed by cases of PG and PGCG. 

  Conclusion: The number of mast cells was more numerous in POF and FH suggesting that mast cell activation is a characteristic feature of chronic inflammation, a condition that may lead to fibrosis as a result of increased collagen synthesis by fibroblasts.