Background: Lichen planus (LP) is a common disorder whose etiopathogenesis is not clear. Recently, it has been suggested that increased reactive oxygen species (ROS) play important roles in the underlying mechanism of LP. Free radicals have an important involvement in the underlying mechanism of lichen planus and also various skin diseases. The aim of the study was to evaluate serum uric acid (UA) levels as a measure of the antioxidant defense status in lichen planus patients. Methods: A case control study was performed on 17 patients with lichen planus and 17 healthy subjects as a control group. We estimated Serum level of uric acid and ascorbic acid using ELISA. Results: The mean of serum levels of uric acid and ascorbic acid was lower in patient group compared to healthy group with no significant difference between the two studied groups. Conclusion: Lichen planus pathogens are not specifically affected by antioxidants as uric acid and ascorbic acid. However, in addition to other interactive variables, the difference in the level of serum for these anti-oxidants between lichen planus patients and healthy subjectsalbight not important– may suggest their involvement