Background: Tranilast, N-(3′,4′-dimethoxycinnamoyl) anthranilic acid (N-5′), which was initially identified as an anti-allergic agent, is also known to have anti-fibrotic potential by inhibiting the proliferation of fibroblasts and collagen deposition. Previous clinical studies on the efficacy and safety of systemic treatment of tranilast on fibrotic skin diseases, such as keloid or hypertrophic scar, are limited. Objectives: To evaluate the safety and efficacy of oral tranilast in treatment of keloid scars Methods: We performed a retrospective observational study of patients with keloids who had been prescribed oral tranilast for more than 3 months. Scar improvement and patient satisfaction were assessed using the Vancouver Scar Scale (VSS) score and the 5-point patient self-assessment score. Any side effects including abnormality in routine lab tests during the treatment period were noted. Results: Of the 42 patients, 27 (64.3%) were female. The mean duration of prescription was 115 days. Significant improvement of total VSS (9.50 vs. 5.62, p<0.001) was noted, along with the subjective improvement of patient-reported symptoms. There was no specific drug-related side effect, and the laboratory tests revealed no significant change. Conclusion: Our study showed that oral tranilast is and effective and well-tolerated treatment for keloid scar. Optimization of treatment with other therapeutic modalities is necessary to develop a more standardized treatment protocol.