Objective: The purpose of this study was to evaluate the usefulness of topical sulfasalazine in the treatment of oral lichen planus (OLP) resistant to corticosteroid therapy. Method and Materials: Twenty-one unresponsive OLP patients were treated with topical sulfasalazine 3 times a day for 4 weeks. Each patient's symptoms and lesion size were evaluated at the beginning of therapy, and then after 4 weeks to determine the efficacy of topical sulfasalazine. Inflammatory cytokines levels in saliva were measured by ELISA. Results: Seventeen patients (81%) reported improvement of discomfort and 12 patients (57%) had lesions decrease in size over 50%. Patients who had higher levels of IL-1β and IL-8 were more responsive to topical sulfasalazine therapy. Conclusion: Topical sulfasalazine should be considered when OLP does not respond to corticosteroid therapy. Furthermore, high concentrations of IL-1β and IL-8 in the saliva are useful indicators for the application of topical sulfasalazine in OLP patients refractory to steroid treatment. Keywords: sulfasalazine, topical application, unresponsive oral lichen planus