Bisehri booti (Aerva lanata (Linn.) Juss.; Family Amaranthaceae) has been used in traditional systems of medicine since long time to treat many diseases including infectious diseases. However, information to revalidate its use on scientific parameters is limited. Therefore, present study has been done to screen antibacterial activity of ethanolic extracts of Bisehri booti against pathological bacterial strains using disk diffusion method and its efficacy was compared with the standard drug ciprofloxacin for Gram-positive and gentamycin for Gram-negative bacterial strains. Qualitative analysis of the extracts was also done to confirm the presence of various phytoactive constituents. It was found that Bisehri booti contains alkaloids, glycosides, flavonoids, carbohydrates, starch, saponin, resins and terpenes. This study scientifically validates the antibacterial potential of Bisehri booti and reconfirms the claims of Unani physicians for it use in various infectious diseases as urinary tract infections, leprosy, dysentery, typhoid, wounds etc. The findings can usefully be applied by researchers elsewhere for comparison of its bioactive constituents and this might be a helpful lead in the rational use of Bisehri booti.