Introduction: Oral Lichen planus is a premalignant condition a distinctive muco–cutaneous disorder that affect skin, mucous membrane, nails and hair. The malignant transformation potential has been subject of controversy in lichen planus, the most common complication being transformation to squamous cell carcinoma. Therefore the present study was conducted to compare the dysplastic expression in oral lichen planus by toluidine blue staining, histopathology and immunohistochemistry (IHC) using CK 19 marker expression. Objectives: To compare dysplasia in Oral lichen planus by clinical, histopathological and IHC using CK 19 marker. Materials and Methods: Prospective comparative study was conducted on 15 patients who were found positive clinically with lichen planus and there after comparing the dysplasia using toluidine blue staining, histopathology and Immunohistochemistry using CK 19 marker. Statistical analysis was done using SPSS version 16 Results: Of the 15 patients who were clinically suspected to have oral lichen planus, 8 (53.3%), 3(20 %) and 1 (6.6%) cases were found to be positive on toluidine blue staining, histopathology and immunohistochemistry respectively. Conclusion: Diagnosis of OLP is done mainly based on clinical and histological examination. In vivo staining of OLP with toluidine blue has not been found to be sensitive enough to identify clinically suspicious cases.