The plant Leucas aspera is claimed to possess anti-inflammatory and anti-rheumatic potential by traditional practitioners. The aim of this study is to validate the traditional claim. The hydroalcoholic extract of aerial parts of L. aspera (HAELA) was orally tested at a dose of 100 mg/kg bodyweight for anti-arthritic effect in adjuvant-induced arthritic rats. Group I rats served as vehicle control group [0.2% carboxyl methyl cellulose (CMC) p.o.]. The test groups were injected with 0.1 ml of complete Freund′s adjuvant into the subplantar region of right hind paw. Group II animals served as disease control, while the group III and group IV arthritic rats were treated with standard drug diclofenac sodium (0.3 mg/kg) and HAELA (100 mg/kg) for 21 days. Activities of inflammatory markers such as tumour necrosis factor-α, C-reactive protein, interleukin-2, cathepsin D and antioxidant enzymes superoxide dismutase (SOD), glutathione peroxidase (GPx) and catalase (CAT) were estimated in plasma/haemolysate and tissue of control and arthritic animals. Histopathological analysis of knee joints was also performed. Statistical analysis of the biochemical parameters was performed by one way analysis of variance (ANOVA) using SPSS software package. Results were expressed as mean±SEM for six rats in each group. P<0.05 was considered to be significant. HAELA showed significant anti-inflammatory (P<0.001) and antioxidant activity (P<0.001) at the specified dose. It did not show mortality up to 2000 mg/kg body weight. Histopathological studies confirmed cartilage regeneration and near normal joint in HAELA treated rats. It can thus be concluded that HAELA possesses significant antioxidant and anti-arthritic potential.