INTRODUCTION:Oral lichen planus is an autoimmune disorder of unknown etiology. It is believed that oxidative stress plays an important role in its pathogenesis. Topical corticosteroids are the gold standard treatment for oral lichen planus. However, for resistant and severe lesions systemic corticosteroids are indicated. The side effects of oral steroids necessitate searching for safer lines of treatment. Lycopene is an antioxidant with promising effects on human health. It is also found to play roles in the treatment of various oral mucosal diseases especially oral lichen planus. OBJECTIVES: The aim of this study was to evaluate the effect of oral lycopene and systemic steroids in the treatment of erosive oral lichen planus and compare between the two therapeutic modalities. MATERIALS AND METHODS: Twenty patients were recruited and randomly assigned in one of two groups, the test (lycopene) and control (corticosteroids) group. Subjective assessment using Visual Analogue Scale and objective assessment using Thongprasom et al. lesion scoring were taken at baseline and after one, two and five months from baseline (three months after treatment termination). RESULTS: In both study groups, there was a significant decrease in the scores of objective and subjective outcomes after one, two and five months. The mean score values of both outcomes were in favor of the test group after two and five months. However, there was no statistically significant difference between the test and control groups throughout the study period. CONCLUSIONS: Lycopene is an effective therapeutic modality for erosive oral lichen planus.