Evaluation of antioxidant properties of medicinal plants from Indian Himalayan region has been very rarely carried out. Withania somnifera L. is one of the commercially available and most preferred medicinal plants in the Himalayan region due to its aphrodisiac property and potential to cure various diseases. The review of literature has indicated that the antioxidant activities of W. somnifera have not been carried out for so long. Therefore, in the present study an attempt was made to evaluate the antioxidant properties of W. somnifera collected from two different habitats that is, forest and roadside at Kullu, north-west Himalaya. The total phenolic and flavonoid contents and DPPH (1, 1-Diphenyl-2-pycrylhydrazyl) scavenging potential of leaves extract of W. somnifera varied significantly between the habitat (p< 0.05). The results further showed that the DPPH scavenging potential of leaves extract at forest site was found significantly higher that is 51% over the roadside. The study indicates that antioxidant activities of leaves of W. somnifera L. varies habitat to habitat and antioxidant properties decrease if plants are exposed to vehicular pollution. Therefore, plantation and cultivation of this species in vehicular pollution free areas are suggested.