Adhatoda vasica L. is a medicinal plant, known as Malabar nut in English, belonging to the family Acanthaceae. It has been used traditionally to treat respiratory disorders like severe coughs, colds, chronic bronchitis, asthma, tuberculosis, and other illnesses. The multifunctional range of bioactives found in it has piqued the interest of pharmaceutical companies, who are looking for more evidence-based ways to develop new formulations. To analyse the A. vasica leaves by GC-MS technique and evaluation of its antioxidant activity. Methanolic extract of A. vasica L. (MEAV) leaves was analyzed by GC-MS for identification and characterization of its bioactives and traditional therapeutic claims. A widely anticipated 2,2-diphenyl-1-picrylhydrazyl (DPPH) method was used to determine the antioxidant activity of MEAV. The major compounds revealed in MEAV leaves are: 1,3,5-triazine-2,4,6-triamine (3.06%); 2,3-dihydro-3,5-dihydroxy-6-methyl-4H-pyran-4-one (5.35%); 5-hydroxymethylfurfural (16.82%); 2-butylphenol (6.85%); 3,4-dihydroxy-5-methyl-dihydro-furan-2-on (2.5%); 2(OR 3)-(1,1-dimethylethyl)-4-methoxyphenol (3.52%); megastigmatrienone 3 (1.02%); tetradecanoic acid (1.52%); vomifoliol (0.58%); oxalic acid, cyclobutylhexyl ester (6.03%); hexadecanoic acid (6.06%); 4-ethyl-2-oxo-2,5,6,7-tetrahydro-1H-cyclopenta[B]pyridine-3-carbonitrile (10.08%); phytol (2.01%); and vitamin E (3.18%). A significant reduction in free radicals against DPPH was observed, which revealed the antioxidant potential of MEAV. MEAV consists of both polar and nonpolar components. GC-MS analysis was used to identify these compounds. The current work validates that the antioxidant activity of MEAV is attributed to the presence of compounds such as vitamin E and terpenes. This work validates the antioxidant activity of methanolic extract of A. vasica attributed to the presence of compounds like vitamin E and terpenes.