The herbal plant Murraya koengii is currently used in medicinal practices for treating various diseases. The present study was carried out to synthesize silver nanoparticles from the leaves of Murraya koengii and its antifungal activity was determined against four micro organisms. From this present study, it was found that the silver nanoparticle which was synthesized from plant extract shows highest activity against Trichoderma and Rhizopus and mild activity against Aspergillius niger and Aspergillus flavus. The highest zone of inhibition was observed in Trichoderma. But the silver nanaoparticle was more active against Rhizopus than the standard antibiotic Amphotericin and plant extract.