Oral lichen planus (OLP) is autoimmune disease that appears on the oral mucosa only, or in combination with skin lesions. The occurrence of squamous cell carcinoma in areas of lichen erosions makes it necessary to follow up patients suffering from chronic lesions. Prevalence in general population varies from 0.9% to 1.2% and varies in different ethnic groups. It is known that cell-mediated immune mechanisms and genetic factors underline OLP pathogenesis. We tested 50 OLP unrelated patients (5 males) for HLA A and compared them to 1089 healthy controls. OLP patients had 3 times less frequently HLA A w19 and 5 times less frequently HLA A28, compared with controls. Erosive OLP type had 4 times less frequently HLA A11 and 2 times less frequently HLA A26 than plaque form. In conclusion, HLA A w19 and A28 appeared associated with OLP in particular, while HLA A11 and A26 with erosive types of OLP.