Abstract Objectives Antibiotic resistance is rising, prompting innovative strategies for eradicating the epidemic. This study investigated the antibacterial properties of the leaves of a widely used medicinal plant, Adhatoda vasica. Methods The plant’s polar (water, methanol) and non-polar (hexane) extracts were tested against several different bacterial strains using the disc diffusion technique. Results In a study, it was found that the water extract had the greatest inhibitory effect on Staphylococcus simulans and Staphylococcus aureus, with minimum inhibitory concentrations of 16.444 and 19.315 g/mL, respectively. Gram-negative strains were more susceptible to plant extracts than Gram-positive strains. The phytochemical analysis indicated the presence of secondary metabolites such as alkaloids, saponins, flavonoids, tannins, and steroids, where absorbance was recorded at 415 nm. The water extract had the highest amount of phenolics, with a total phenolic content of 53.92 0.47 mg and a total flavonoid content of 7.25 0.08 mg. Results suggest that the extract may have potential therapeutic applications for antimicrobial properties. Conclusions The study concluded that the extract’s phenolic group of secondary metabolites were responsible for its antibacterial activity. The study highlights A. vasica as a promising source for discovering new and effective antibacterial compounds.