ABSTRACT:Oral lichen planus (OLP) is the most common noninfectious oral disease and is considered a potentially malignant disorders (OPMDs). The etiology and pathogenesis of OLP are not completely understood and the malignant transformation remains under discussion. The aim was to asses the cytological and histological features of OLP, and establish relationship between clinical and microscopic profiles. A total of 10 patients diagnosed with OLP were investigated. Slides were prepared and stained with Hematoxylin-Eosin to identify 8 histological features and 8 cytological alterations. Finally, oral epithelial dysplasia degree was determined. Hyperplasia and loss of polarity of basal cells were detected in 90 % of cases. Anisonucleosis, nuclear pleomorphism and hyperchromasia affected 100 % of the sample. Six cases were classified as mild-grade OED, with no cases of severe-grade. Microscopic alterations were higher in women (P <0.0001) and moderategrade OED was diagnosed only in this group (P <0.0014). The findings demonstrated that microscopic and clinical data association should be analyzed to a better understand of disease behavior. OED was absence only in one case, so the periodic follow-up of patients diagnosed with OLP is mandatory to avoid the malignant transformation.KEY WORDS: oral epithelial dysplasia, oral lichen planus, potentially malignant disorders.