Withania somnifera (L) Dunal popularly known as ‘Aswagandha’ has been an important herb in the Ayruvedic and indigenous medical systems for centuries in India. To validate this use, leaves of the plant was subjected to preliminary phytochemical analysis and in vitro antibacterial activity against Staphylococcus aureus, Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, Proteus mirabilis and Salmonella paratyphi B. Acetone extract demonstrated highest antibacterial activity followed by ethanol extract. Aqueous extract showed minimal antibacterial activity against most of the test bacterial pathogens. Preliminary phytochemical analysis revealed the presence of carbohydrates, glycosides, alkaloids, phytosterols, fixed oils, phenolic compounds and flavonoids in extracts. Our findings suggest that an appropriate bioactive compound may be developed from leaves of Withania somnifera (L.) Dunal as an alternate to antibiotics.