The clinical presentation and course of lichen ruber planus (LRP) of the oral mucosa are significantly different from its manifestations on the skin. A variety of clinical manifestations and a low efficacy of treatment cause certain difficulties and interest not only to dentists but also to dermatologists in terms of diagnosis and treatment of LRP of the oral mucosa. Aim. The aim of the study was to identify the clinical features of different forms of LRP of the oral mucosa. The study included 147 patients with different forms of LRP of the oral mucosa, aged from 24 to 70 years. Results. The study results demonstrate that most of the patients were aged 40 years and older, with females constituting the vast majority — 95%. Among all the disease forms, the erosive-ulcerative form was diagnosed most often — in 49 (33%) of the patients. In addition, all the examined patients were detected with a combination of LRP of the oral mucosa and another somatic pathology, which requires consultations by appropriate specialists for an adequate treatment regimen.