The aim of the study was to evaluate the antioxidant and free radical scavenging properties, total phenolic contents and antibacterial activities of the methanol extract of Mentha longifolia Linn. Hudson. growing in the high altitude cold desert region of Ladakh, Jammu and Kashmir, India. The antioxidant activities of the extracts were investigated with four different methods such as 2,2’-diphenyl-1-picrylhydrazyl radical (DPPH), 2,2’-azinobis (3-ethylbenzothiazoline-6-sulfonic acid) radical (ABTS), Reducing power assay and Ferric reducing antioxidant property (FRAP). M . longifolia exhibited the strongest activity as ABTS scavenger compared to DPPH and FRAP. All the assays carried out found that the plant has antioxidant potential. The total polyphenol content (TPC) and total flavonoid content of the extract was determined as 107.208 ± 34.2 mg GAE/g dry wt. and 42.47 ± 7.97 mg QE/g dry wt. respectively where 39.61% of TPC were flavonoids. A high correlation was found between the DPPH and ABTS free radical scavenging potency (R2 = 0.869). The study has validated the medicinal potential of Mentha longifolia Linn. Hudson and revealed that the consumption of the plant could be beneficial as it possesses the desirable quality of antioxidant activity.