Hibiscus syriacus is an ornamental plant, and it also has uses in traditional medicine. This study aimed to investigate in vitro antimicrobial activity and the biochemical composition of Hibiscus syriacus. In this study, the biochemical composition of ethanol extracts of H. syriacus flowers (HSFEt) and H. syriacus leaves (HSLEt) was analyzed by GC-MS. The antimicrobial activity was investigated using a disk diffusion test against 39 bacteria (including 11 multidrug-resistant strains) and 2 fungi strains. 21 and 12 components were identified in HSFEt and HSLEt, respectively. The main component is 2,3-Dihydroxypropyl stearate in both extracts. HSFEt and HSLEt have antimicrobial activity against most of the tested microorganisms. It has been detected the highest activities against Staphylococcus aureus ATCC 25923 (ST11) with a 15 mm, Staphylococcus aureus (CI1) and Staphylococcus aureus MRSA+MDR (MDR9) with a 14 mm inhibition zones in HSFEt, and Staphylococcus aureus ATCC 25923 (STI1) with an 11 mm inhibition zone in HSLEt. All these results showed that a syriacus has antistaphylococcal potential.