Statement of Problem: Oral lichen planus (OLP) is a common chronic immunologic mucocutaneous disorder with various types. Erosive and bullous types are painful and require treatment. In treatment of Lichen planus, various topical and systemic corticosteroids are used.Purpose: The purpose of this study was to compare the effects of Adcortyl (Triamcinolone in orabase) and triamciniolone mouthwash in the treatment of oral lichen planus.Materials and Method: This experimental study was conducted on 60 patients in two equal groups affected by erosive or atrophic lichen planus. Type and size of the lesions were gathered by mm2 and the severity of pain by VAS. The first group was treated with %0.2 triamciniolone mouthwash and the second group by Adcortyl (triamcinolone in orabase). The patients were evaluated after one month. The size of lesions and severity of pain were recorded and compared before and after treatment. The data were analyzed using T- test.Results: This study showed a significant reduction in the size and severity of pain of the lesions after treatment using %0.2 triamcinolone mouthwash and Adcortyl in each group, but the difference between the two groups was not significant.Conclusion: Adcortyl and triamcinolone mouthwash were useful in healing and reduction of pain from lesion.The properties of triamcinolone mouth wash including internal production of triamcinolone ampoule, easy formulation and availability, convenient use, contact with the distal surfaces of the oral cavity, and preventing new eruptions introduces it as a useful drug to control the symptoms of OLP.Key words: Triamcinolone, oral lichenplanus, Pain