Abstract: We have used 12 Epulis taken during surgical operation and as control, some normal gingival specimen. The aim was to clarify the relationship between the degree of inflammation and NO production in several cases of Epulis, exhibiting different degree of inflammatory process and verifying the presence of cells involved in NO production. From the immuhistochemical data in our possession we can conclude that NO is one of the factor which module the pathogenecity degree of Epulis.