Abstract. Rheumatoid Arthritis (RA) is a chronic inflammatory disorder and sodium diclofenac as symptomatic management of RA but in long-term used would has gastrohepatology side effect. Previous studies reported onion skin extract has antiinflammatory effect as an alternative approach in treatment RA symptoms. This study aimed to observe the histological changes in rat’s intraarthicular joint induced with Complete Freunds Adjuvant (CFA) treated with onion skin extract. The method is an Experimental Study with post-test control group design. Arthritis was induced by intraarticular of Complete Freund Adjuvant (CFA) on the right back knee of rat. Eighteen rats were randomly divided into six groups, first group as a normal control, and five other groups were induced with 100 µg CFA, then these groups were treated differently. One of five group induced as negative control.Three groups were treated orally with onion skin extract in doses 100,200,300 mg /kg body weight and one group treated orally with sodium diclofenac in doses 10 mg/kg body weight as positive control. This study showed that onion skin extract prevents some principal signs of arthritis and significantly reduces the joint damage (p=0,00053)