The current research investigation demonstrated that the aqueous leaves extract of Rosamarinus officinalis possesses cardinal phyto-chemicals to fabricate AgNPs in an eco-friendly way. The phyto-synthesized AgNPs were characterized to be stable, monodispersed, polycrystalline and mostly spheroidal in conformation. The nano-spheriods were observed to be 25-75 nm in diameter, displaying λmax peak at 430 nm. From the comparative antimicrobial investigations, it was observed that AgNPs manifested tremendous bactericidal properties against all test organisms particularly S. epidermis (89%), S. aureus (84%) and K. pneumonia (84%), owing least MIC values of 40µL. The aced fungicidal activity was also exhibited by AgNPs against all fungal test species particularly C. herbarum (90%), A. flavus (85%), R. stolonifer (85%) and C. jadinii (85%). In contrast to AgNPs, all crude ethanolic, aqueous, methanolic and n-hexanoic extracts manifested less to moderate antimicrobial activity against all test micro-organisms with three-fold escalating MIC values i.e., 160µL.