Corticosteroids are the mainstay for treatment of oral lichen planus (OLP) and have their own side effects. The aim of this study was to compare the therapeutic effects of aloe vera (AV) mouthwash with triamcinolone acetonide 0.1% (TA) on OLP. A total of 46 patients with OLP were enrolled in this study. The patients were randomly divided into 2 groups. Each group was treated with received AV mouthwash or TA. The treatment period for both groups was 4 weeks. The basement data were recorded for each patient. Patients were evaluated on days 8, 16 and after completing the course of treatment (visit 1-3). The last follow-up was 2 months after the start of treatment (visit 4). Visual analogue scale was used for evaluating pain and burning sensation and Thongprasom index for clinical improvement and healing. In addition, lesion sizes were measured and recorded at each visit using a grid. Baseline characteristics, including pain and burning sensation score, size and clinical characteristics of the lesions according to Thongprasom index, were not different between the 2 treatment groups. Both AV and TA significantly reduced visual analogue scale score, Thongprasom score and size of the lesions after treatment (P < 0.001) and after 2 months of discontinuation of the treatment (P < 0.001). In the AV group, 74% of patients and in the TA group 78% of patients showed some degrees of healing in the last follow-up. AV mouthwash is an effective substitute for TA in the treatment of OLP.