In this study, we analyzed Ki67 and cyclin D1 immunoexpression in 44 oral squamous cell carcinomas from various anatomical sites. Ki67 immunoreaction was identified in all analyzed cases and presented an index of proliferation of 22% for well-differentiated carcinomas, 32% for moderately differentiated and 53% for the poorly differentiated ones. In case of cyclin D1, the mean positivity index was 8% for well-differentiated carcinomas, 18% for moderately differentiated and 34% for the poorly differentiated carcinomas. The analyzed biomarkers prove useful to identify lesions with poor differentiation and invasive behavior.