10.22376/ijpbs.2019.10.1.p1-12 Volume 6 Issue 2 2015 (April - June) Nanotechnology is being paid vast attention in this century for its intrinsic characters at the nanoscale level. This is due to the particles possessing high surface area to volume ratio, which can be modified or manipulated to achieve defined and improved surface properties. Among the nanometer particles so far reported, silver is versatile since it has a wide range of biomedical applications. In the current study, silver nanoparticles were synthesized from silver nitrate solution by using the aqueous fruit filtrate of lessThan i greaterThan Citrus sinensis lessThan /i greaterThan . There was a change of colour from colourless solution to dark brown, which indicated the reduction of silver ions due to surface plasmon resonance. The particles were absorbed in the UV range and the corresponding peak displayed at 417nm. The characterization study was carried out by using SEM and the percentage of silver nanoparticles was identified by using EDAX. The antimicrobial activity of the particles was checked against lessThan i greaterThan E.coli lessThan /i greaterThan (ATCC 25922) and lessThan i greaterThan P.aeruginosa lessThan /i greaterThan (ATCC 27853). D.SUBHASHINI Citrus sinensis, Phyto synthesis, Silver nanoparticles, Antimicrobial activity. 396-403