The aim of this study is to evaluate the therapeutic potential of the Schiff Base {2-[(1E)-N-{2-[(2-{(Z)-[1-(2-Hydroxyphenyl) Ethylidene] Amino} Ethyl) Amino] Ethyl} Ethanimidoyl] Phenol} in adjuvant-induced rheumatoid arthritis in rats. The study involves immunizing the rats with a sub-plantar injection of 0.1 mL of Mycobacterium tuberculosis in incomplete Freund’s adjuvant. One hour after the injection, the rats are treated orally with 1 mL of Schiff Base at doses of 5 and 10 mg/kg. The results obtained after treatment with Schiff Base show a highly significant reduction in the arthritic score and the thickness of the rat paws starting from day 6. This reduction in arthritis is manifested by the inhibition of inflammation (reduction in joint swelling and inhibition of immune cell infiltration). An improvement in oxidative stress markers was observed. Our results reveal a significant increase in catalase activity with both concentrations compared to the arthritic group. The best protection against arthritis was observed with the 10 mg/kg/day concentration. In conclusion, the synthetic Schiff Base is a potent treatment for rheumatoid arthritis.