Objective: Barleria lupulina Lindl (Acanthaceae) (B. lupulina) has been traditionally used in the treatment of rheumatoid arthritis but, no scientific data has been published supporting the claimed ethnomedical use. This study was designed to investigate the anti-arthritic potential of B. lupulina leaves and its role in immunomodulation. Methods: Methanol extract of B. lupulina (MEBL) leaves (300 and 600 mg/kg BW) was tested for its antiarthritic activity by various models namely, formalin-induced arthritis, adjuvant induced arthritis, collagen type II-induced arthritis and monosodium iodoacetate induced osteoarthritis. Immunomodulatory activity of the same was tested by measuring WBC Count, Spleen Weight, Spleen WBC Count and Delayed Type Hypersensitivity (DTH) Reaction.Results:MEBL extracts 300 mg/kg and 600 mg/ kg showed statistically significant inhibition (P<0.05 and P<0.001) of the edema formation and Myeloperoxidase (MPO) during experimental period and activities of antioxidants were restored significantly. MEBL extracts 300 mg/kg and 600 mg/kg significantly increased the Hemoglobin (Hb) level, serum albumin, total protein, calcium and phosphorus levels and reverted back the levels of WBC count and Erythrocyte Sedimentation Rate (ESR) (P<0.05 and P<0.01). Histopathological studies of ankle joints also supported this finding. Immunomodulatory study revealed an increase in the blood leukocytes count, weight of spleen, spleenic leukocytes count and increase in paw volume on delayed type hypersensitivity footpad thickness suggesting an uplift of immune status. Conclusions: The present study concluded that, MEBL holds antiarthritic and Immunomodulatory activity. Although subsequent study is required to evaluate the active constituents responsible for the activity.