Abstract: Zanthoxylum nitidum (Roxb.) DC (Rutaceae), called Tez-mui or Tejamool in Assamese is a large prickly shrub occurring in North-East India and its roots are used traditionally for several medicinal purposes. In present study the methanol extract of roots from Zanthoxylum nitidum (ZNME) was evaluated for its ntiinflammatory activity in acute (carrageenan, histamine and serotonin induced rat paw oedema) and chronic models (cotton pellet induced granuloma). In all models the ZNME (75 and 150 mg/kg body wt. p.o.) exhibited significant antiinflammatory activity (p < 0.001) in a dose dependent manner when compared with saline control. Indomethacin (10 mg/kg body wt. p.o.) was used as reference drug. The ZNME was evaluated for its antioxidant properties by 1,1-diphenyl-2-picryl hydrazyl (DPPH) radical scavenging assay and in vitro lipid peroxidation induced by the Fe2+- ascorbate system in rat liver homogenate. In DPPH radical scavenging assay, the ZNME demonstrated marked and dose dependent free radical scavenging effect and the mean inhibitory concentration (IC50) of the ZNME was found to be 75.2 µg/ml, while the ascorbic acid (reference) exhibited 43.7 µg/ml. The ZNME effectively inhibited the lipid peroxidation in a dose related manner showing the IC50 value of 279.1 µg/ml, whereas the quercetin (reference) showed 46.6 µg/ml. These findings revealed that the Z. nitidum root had remarkable acute and chronic anti-inflammatory and in vitro antioxidant actions in the tested models validating its traditional uses.