BACKGROUND Oral lichen planus (OLP) and oral lichenoid lesions (OLL) are considered potentially malignant oral disorders, presenting with similar clinical and histopathological manifestations that make differential diagnosis difficult and reinforce the need for new techniques for their evaluation. OBJECTIVE This study aimed to compare the histomorphometric characteristics of OLP and OLL. METHODS This retrospective cross-sectional study was based on 30 histological sections of incisional biopsies of OLP and OLL stained with hematoxylin-eosin for the analysis of morphological parameters, such as keratosis, acanthosis, inflammatory infiltrate band, eosinophilic band, degeneration of the basal layer, involvement of the epithelium-chorion interface, and degree of subepithelial inflammatory infiltrate; and morphometric parameters, such as keratin thickness, distance from the basal layer to the epithelial surface, and thickness of the inflammatory infiltrate band. Chi-square and Fisher's exact tests were used to compare categorical variables and injury types. The t-test was used to compare morphometric variables between the two types of injury. RESULTS There was no significant association between the type of lesion and the clinical characteristics of the patients (p > 0.05). The degree of dysplasia, used as an inclusion criterion, was associated with lesion type (p = 0.0003). There were no significant differences between the morphometric variables evaluated for the two types of lesions (p > 0.05). CONCLUSIONS Based on the methodology used and the sample established for this study, there were clinical and histomorphometric similarities between OLP and OLL. This justifies further discussion on whether these lesions are a spectrum of presentations of the same condition or truly distinct conditions.