Background : Micronuclei in exfoliated oral epithelial cells have been shown in some studies to correlate with severity of this genotoxic damage. This severity can be measured in terms of grading of the lesions. Aim : To correlate frequency of micronuclei (MN) in oral exfoliated cells in clinically diagnosed cases of oral squamous cell carcinoma (OSCC) followed by a histopathological grading. Materials and Methods : The study subjects consisted of clinically diagnosed cases of OSCC. Healthy subjects without any tobacco consumption habits formed the control group. The cytosmears from both groups were stained with rapid Papanicolaou stain. MN were identified according to the criteria given by Countryman and Heddle with some modifications. Results : The frequency of MN was three to four times higher in patients with OSCC as compared to patients in the control group and the difference was found to be highly significant. In 75% cases, the cytological grade as determined by the frequency of micronuclei correlated with the histopathological grade and this observation was statistically significant. Conclusions : MN can be a candidate to serve as a biomarker for prediction of the grade of OSCC.