In the present study, the methanol extract of stem bark of $Zanthoxylum$ $nitidum$ (ZNME) was evaluated for its anti-inflammatory activity in acute (carrageenan, histamine and serotonin induced rat paw oedema) and chronic model (cotton pellet induced granuloma) along with reference drug indomethacin (10 mg/kg body wt. p.o.). The ZNME (75 and 150 mg/kg body wt. p.o.) exhibited significant activity ($p$ <0.001) against all phlogistic agents employed in a dose dependent manner. In chronic model also the ZNME caused a significant ($p$ <0.001) and dose dependent inhibition of granuloma formation. 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 $Fe^{2+}$-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 ($IC_{50}$) of the ZNME was found to be 77.8 ${mu}g$/ml, while the ascorbic acid (reference) exhibited 43.7 ${mu}g$/ml. The ZNME effectively inhibited the lipid peroxidation in a dose related manner showing the $IC_{50}$ value of 297.9 ${mu}g$/ml, whereas the catechin (reference) showed 46.64 ${mu}g$/ml. These findings reveal that the ZNME possessed promising acute and chronic anti-inflammatory and $in$ $vitro$ antioxidant actions in the tested models.