To evaluate phytochemical constituents and antioxidant potential of methanol aerial parts (leaf and stem) extract of Mentha arvensis L from Kashmiri Himalaya region. The extract shows the presence of flavonoids, saponins, alkaloids, steroids, carbohydrates, proteins, tannins and phenolics. The antioxidant activity of methanol aerial extract of Mentha arvensis L was evaluated by using 1,1-diphenyl, 2-picrylhydrazyl (DPPH) scavenging and reducing power assays. The total phenolic and total flavonoid content (mg/g) was found to be 672.11 and 283.1 respectively. The percentage inhibition of DPPH scavenging was found to be 81.33% at concentration of 0.5mg/ml. The reducing power was found to be 0.76 at 0.1mg/ml and increased to 2.42 at 0.5mg/ml. The results obtained revealed that methanol extract from aerial parts of Mentha arvensis L can be promising candidates for natural sources of antioxidants with high activity.