Marwa Mokhtar Mohammed *,  SheriefyousefElnagdy**, sohierabdelgaber*** and  Doaaabdelallahfarag**** * Teaching assistant ,Department of Oral Pathology,  Faculty of dentistry,,Mansoura University. ** Professor and  Head of Oral Pathology departmet, Faculty of dentistry, Mansoura University. ***Assistant professor of dermatology, faculty of medicine, Mansoura University.  **** Assistant Professor of Oral and Maxillofacial Pathology,  Faculty of dentistry, Mansoura University. Abstract: Background: Oral lichen planus (OLP ) is achronicmucocutanous disease, although the etiology of oral lichen planus remains unclear, accumulating evidence supports arole of immune dysregulation in the pathogenesis of OLP, especially a T-cell mediated immune response and the abnormal production of various inflammatory molecules.  Aim of the study: This study was conducted to examine the expression of NF-KB and IL 17  in studied OLP cases and correlates the expression with clinicopathological parameters.  Material and methods: thirty cases of OLP will be included in this study . Four micron sections were prepared for immunohistochemical staining with NF- κB and IL 17Kruskalwallis&chi square test were used for the statistical analysis of the results. Results: In the present work, 90% of studied OLP cases showed immunoreactivity for NF- κB and 87% were positive for IL 17. There was positive correlation between both markers expression and clinical forms of OLP. Conclusions:The present study supports the notion that up-regulation of both NF-κB and IL`17 in OLP correlates with the degree of inflammatory cell infiltration.  And the statistically significant correlation of  NF-κB and IL 17 in OLP cases observed in this study suggests their role in the pathogenesis of OLP.