Objectives E-cadherin is a transmembrane glycoprotein, which is responsible for cell adhesion and its expression decreases in dysplastic lesions. This study aimed to assess the expression of this marker in oral lichen planus (OLP) with and without dysplasia to assess its potential for use as a predictor of malignant transformation.Methods This descriptive, cross-sectional study was conducted on 44 OLP specimens using immunohistochemistry (IHC) by streptavidin- biotin technique. For this purpose, E-cadherin antibody was used and the intensity score (IS), proportional score (PS) and total score (TS) were calculated. Data were analyzed using SPSS version 21. The relationship between the intensity of expression of E-cadherin and dysplastic changes was assessed using the Mann Whitney U test. P < 0.05 was considered significant.Results The TS of E-cadherin expression was 3 to 6 and 3 in the superficial and deep layers of 100% of specimens with dysplasia, respectively. The TS of E-cadherin expression was 3 to 6 in the superficial layer of 82.5% of specimens and 3 in deep layers of 81.2% of specimens without dysplasia. According to the Mann Whitney U test, the expression of E-cadherin in the superficial (P = 0.90) and deep (P = 0.35) layers was not significantly different between the two groups of OLP with and without dysplasia.Conclusion No significant difference was found in the expression of E-cadherin in OLP specimens with and without dysplasia. It may be concluded that in contrast to other preneoplastic lesions, dysplastic changes of OLP do not follow other malignant transformation patterns in the oral mucosa.