Abstract: Background and Objectives: Cytokines and oxidative stress biomarkers are elevated in arthritis. This study therefore investigated the effects of petroleum ether, ethanol and ethyl acetate extracts of Trichilia monadelpha stem bark on haematological profile, serum cytokine levels and tissue oxidative stress biomarkers in arthritic rats. Methodology: Hematological profile, assay of interleukin-6 and tumour necrosis factor-α, tissue proteins as well as malondialdehyde, myeloperoxidase and superoxide dismutase in arthritic tissue was carried out in groups of CFA-induced (sub-plantar injection of 0.1 mL of 5 mg mL–1 of heat killed Mycobacterium tuberculosis in paraffin oil) arthritic Sprague-Dawley rats treated with either 10, 30 and 100 mg kg–1 of the extracts, 0.3-3.0 mg kg–1 dexamethasone or 0.1-1.0 mg kg–1 methotrexate over a 28 day period. Results: The extracts restored (p<0.01-0.0001) the significantly elevated WBCs, neutrophils and lymphocytes and the significantly reduced RBC and haemoglobin, associated with arthritis, to normal. The extracts (p<0.01-0.001), dexamethasone (p<0.05-0.01) and methotrexate (p<0.05-0.01) significantly and dose-dependently reduced high levels of TNF-α and IL-6 as well as malondialdehyde and myeloperoxidase associated with arthritis, relative to the control. Superoxide dismutase activity also increased significantly (p<0.01-0.0001) with treatments. Conclusion: The petroleum ether, ethyl acetate and ethanol extracts of Trichilia monadelpha stem bark improved haematological features, decreased tissue proteins, cytokines and oxidative stress biomarkers indicating its potent anti-inflammatory and antioxidant property and establishing its usefulness in the traditional management of arthritis.