Background: Total antioxidant capacity (TAC) and malondialdehyde (MDA) levels have not been reported in oral lichen planus (OLP) patients treated with a topical corticosteroid. This study evaluates TAC and MDA levels in unstimulated saliva of OLP patients. Such measurements may need to be supported by clinical observation. Materials and Methods: Twenty patients with OLP participated in a study conducted at the Department of Oral Medicine, Tehran University of Medical Sciences. Salivary TAC and MDA were determined by biochemical analyses before and after 5-week triamcinolone acetonide (0.2%) mouthrinse treatment. Subjective symptoms as well as lesion status pre- and post-treatment were measured using visual analog scale (VAS) and clinical scoring system, respectively. Wilcoxon signed rank test was used for the evaluation of MDA and TAC parameters, VASs, and rates of clinical scores. Spearman's rank correlation was used to determine the relationship between different variables. Results: A statistically significant increase in salivary TAC was found after treatment. There was no significant difference in the reduction of salivary MDA levels in OLP patients after treatment. Conclusion: Posttreatment analyses revealed a significant degree of recovery and pain relief of OLP lesions. Hence, triamcinolon mouthrinse by reducing oxidative stress is an appropriate treatment in OLP patients.