This study was designed to evaluate the efficacy, safety and tolerability of Iguratimod Tablets 25 mg for the treatment of patients with active rheumatoid arthritis. The objectives of this study were percentage of patients meeting ACR20, ACR50, ACR70 response criteria, mean reduction in DAS28 and HAQ score. This was randomized, double-blind, study conducted in nine centers across India. The study was conducted in male or female subjects of the age 18 to 65 years. A total of 243 subjects were randomized in study. The treatment period was 28 wk with follow-up on week 4, 8, 12, 18 and week 24 from the start of treatment. At the end of study, 100% patients achieved ACR20, 73.45% patients achieved ACR50 and 19.47% patients achieved ACR70 criteria in Iguratimod group vs. 97.39% patients achieved ACR20, 61.74% patients achieved ACR50 and 10.43% patients achieved ACR70 criteria in Methotrexate group. The mean change in DAS28 at the end of study was --2.22 vs -2.0 in Iguratimod and Methotrexate group resp. The mean change in HAQ score at the end of study was -0.91 vs -0.77 in Iguratimod and Methotrexate group resp. There were 61 clin. adverse events reported in 45 subjects. No adverse event led to SAE. The add on therapy of Iguratimod Tablets 25 mg to Methotrexate Tablets 15 mg is statistically equivalent in achieving the ACR20, ACR50 and ACR70 criteria and statistically superior to mean reduction in DAS28 and HAQ score as compared to Methotrexate Tablets 25 mg.