In this work, a simple and rapid green approach was employed for the preparation of silver nanoparticles that were successfully synthesized using kumquat aqueous extract and under supporting of microwave as biological reducing agents. It proves to be an eco-friendly, rapid green method for the synthesis providing a cost effective and an efficient route for the Ag nanoparticles’ synthesis. The shape and size of nanoparticles were controlled by the experimental conditions (reaction time (only 13 min for the conversion of silver ions into silver nanoparticles), ratio of kumquat extract and silver nitrate, ect…). Herein, the synthesized Ag nanoparticles were characterized using UV-vis, XRD, TEM and EDS. This green method has been obtained Ag nanoparticles quite uniformly with average diameter around 10-25 nm. Moreover, the synthesized Ag nanoparticles also showed efficient antimicrobial activity against of E. coli bacteria. This eco-friendly method could be a competitive alternative to the conventional physical/chemical methods used for the synthesis of Ag nanoparticles. Thus, it has a potential to use in biomedical applications, opto-electronics and medical devices in future.