ul-e-Tesu (flowers of Butea monosperma; Family Fabaceae) has been reported to be an effective drug in Unani classical literature for treating various diseases including infectious diseases. However, it appears that no work has been done on scientific validation of its use in infectious diseases. Therefore, in the present study in-vitro screening of Gul-e-Tesu has been done for antibacterial activity against bacterial strains using Kirby Bauer’s Disk Diffusion method. The efficacy was compared with the standard drug used as Positive Control and the solvent used to dissolve the test drug- Dimethyl Sulphoxide (DMSO) as Negative Control. Physico-chemical analysis was also done to confirm the presence of various phytoactive constituents present in the test drug. It was revealed that Gul-e-Tesu contains alkaloids, glycosides, flavonoids, carbohydrates, tannins, starch, saponin, resins and terpenes. The study demonstrates the in-vitro antimicrobial effect of Unani drug Gul-e-Tesu.