Oral lichen planus (OLP) is a relatively common chronic inflammatory disorder affecting stratified squamous epithelia. Whereas in the majority of instances, cutaneous lesions of lichen planus (LP) are self-limiting and cause itching, oral lesions in OLP are chronic, rarely undergo spontaneous remission, are potentially premalignant and are often a source of morbidity. Current data suggest that OLP is a T cell-mediated autoimmune disease in which auto-cytotoxic CD8+ T cells trigger apoptosis of oral epithelial cells. The characteristic clinical aspects of OLP may be sufficient to make a correct diagnosis if there are classic skin lesions present. An oral biopsy with histopathologic study is recommended to confirm the clinical diagnosis and mainly to exclude dysplasia and malignancy. The most commonly employed and useful agents for the treatment of lichen planus (LP) are topical corticosteroids but other newer agents are available.