Biological synthesis of nanoparticles has upsurge in the Nano-biotechnology fields to make novel agents which are ecofriendly, effective, and stable with a great importance for different applications. The present study was carried out to evaluate the antimicrobial activity of silver nanoparticles (that synthesized by Cinnamomum zeylanicum plant bark extract) and cefotaxime in vitro and in vivo on induced infected fracture by staphylococcus aureus in rabbit model. The approach of green synthesis seems to be cost effective, eco-friendly and easy alternative to conventional methods of silver nanoparticles synthesis. The powerful bioactivity demonstrated by the synthesizdded silver nanoparticles leads towards the clinical use as antimicrobial and acceleration of infected bone fractures healing.