Trigonella foenum graecum is an Iranian medicinal plant used for the treatment of rheumatoid arthritis and inflammation. The present study was designed to investigate the beneficial outcome of the plant T. foenum graecum on adjuvant-induced arthritis in albino rats. Ethanol extract of T. foenum graecum was tested against Freund's complete adjuvant-induced arthritis in rats. In the present study, paw volume was measured on the 4th, 8th, 14th and 21st day. On day 22, animals were anaesthetized, and blood samples were collected for the estimation of haemoglobin, white blood cells (WBC), differential white blood cells, erythrocyte sedimentation rate (ESR), red blood cells (RBC), interleukins (IL-1α, IL-1β, IL-2, IL-6) and tumour necrosis factor-α (TNF-α). The animals were sacrificed, and the cartilage tissue was isolated for estimation of lipid peroxidation (LPO), superoxide dismutase (SOD) and glutathione (GSH). Administration with both doses of T. foenum graecum (200 and 400 mg/kg) significantly (P < 0.05) decreased the paw oedema and restored body weight. T. foenum graecum significantly (P < 0.05) reduced the differential WBC count, ESR and WBC (5.833 ± 0.703, 6.989 ± 58.5) content and also showed significant (P < 0.05) increase in RBC and Hb (4.783 ± 0.46, 15.46 ± 0.158) content. T. foenum graecum significantly (P < 0.05) decreased the IL-1α, IL-1β, IL-2, IL-6 and TNF-α levels. It also significantly decreased the levels of LPO and increased the SOD and GSH levels in cartilage tissue. In this study, T. foenum graecum 400-mg/kg dose showed more prominent results compared to the 200-mg/kg dose of T. foenum graecum. The results obtained in this study suggest that anti-inflammatory and antioxidant activities of T. foenum graecum may be the possible reason behind the observed anti-arthritic activity.