Abstract : Introduction: Oral submucous fi brosis (OSF) i s t he m ost common potentially malignant disorders which is widely spread and has high malignant transformation rates. The use of immunohistochemical (IHC) studies has become one of the stepping stones to establish new surrogate markers to analyze the malignant transformation of a potentially malignant disorder to malignancy. Oral submucous fibrosis has been classified as stages 1, 2, and 3 according to severity of fibrosis and hyalinization, but the intensity of IHC staining of cytokeratin 19 (CK19) among these stages has not been done to analyze and establish the fact whether the intensity increases according to clinical stages. Materials and methods: Thirty-five cases of OSF were taken according to the clinical stages and an IHC study was done using CK19. The p-value was calculated using Fisher's exact tests. Results: Among 35 cases, 6 cases of stage 1 showed 33.3% of negative, 0% of mild, 50% of moderate, and 16.6% of intense staining. Twelve cases of stage 2 showed 16.6% of negative, 25% of mild, 33.3% of moderate, and 25% of intense staining. Seventeen cases of stage 3 showed 5.8% negative, 47% mild, 35.2% moderate, and 11.7% intense staining. The overall and comparative p-values were insignificant. Conclusion: Since the overall and comparative p-values were insignificant, the present study shows that there is no relation between the clinical stages of OSF and the CK19 staining. Hence, there is no increase in intensity according to clinical stages. Clinical significance: Establishing a direct relation between clinical stages of OSF and many cellular and extracellular proteins through IHC studies would make a well-established proof directly correlating the severity and staging in mouth opening to intensity of CK19. In this study, p-values were less and hence the study showed an insignificant clinical outcome