The antibacterial activities of medicinal plant were evaluated in vitro against human pathogenic microorganisms by Kirby–Bauer agar diffusion method. Methanol and acetone extract of Hibiscus rosa–sinensis, Tabernaemontana divaricata, and Nyctanthes arbortristis were prepared and its antimicrobial property was evaluated against S. aureus, E. coli and P. aeruginosa. Different concentrations (25%, 50%, 75% and 100%) of fresh leaves extracts of all selected plants were used to screen antimicrobial activity.  The results revealed that the methanol extracts of plant leaves have high antimicrobial activities on all test organisms (range of inhibition, 7– 20 mm) as compare to acetone extracts of plant leaves in same concentration. The antimicrobial activity against S. aureus, with maximum inhibitory zone at 100% was shown in methanol extract of H. rosa–sinensis and T. divaricata, whereas against Escherichia coli maximum inhibitory zone was shown in methanol extract of T. divaricata and against Pseudomonas aeruginosa maximum inhibitory zone was shown in methanol extract of T. divaricata and N. arbortristis. Results concluded that these plants contain high amount of secondary metabolites in their leaves extract which enhance its antimicrobial property against human pathogenic microorganisms.