Background: A very high rate of morbidity and mortality is linked to the condition known as rheumatoid arthritis (RA). Objective: The current study has aimed to examine the impact of daily delivery of Withania somnifera (W. somnifera) or Ashwagandha extract (ASHE) and standard drug (Diclofenac potassium) on oxidative stress and inflammatory biomarker in adjuvant-induced arthritis (AIA) in male albino rats. Materials and methods: Animals were divided into ten groups (n=5). Group 1 acted as control, group 2 presented the RA rats and groups 3, 4, 5 were treated with different doses of ASHE (50, 100 and 200 mg/kg, respectively) daily for 3 weeks, Group 6 received standard drug (Diclofenac potassium) at a daily dose of 10 mg/kg for 3 weeks. Groups 7, 8 and 9 represent CFA-induced RA rats, which received tested extract at 50, 100 and 200 mg/kg respectively: daily for 3 weeks. The tenth group represented RA group received standard drug (Diclofenac potassium). Results: The changes induced in AIA rats were evaluated by measurement of oxidant and antioxidant biomarkers as well as interleukins-1β (IL-1β) and tumor necrosis factor alpha (TNF-α), in addition to cyclooxygenase-1 (COX1) and cyclooxygenase-2 (COX2) measurement. W. somnifera dose-dependently alleviated the severity of the disease based on the reduction of lipid peroxidation and ceruloplasmin and improved the GSH, SOD, CAT and TAC as compared to AIA-rats. ASHE reduced the serum level of IL1β, TNF, as well as COX1 and COX2 as compared to AIA-rats. Conclusion: The results of the experiments showed that W. somnifera might be useful for management of RA.