The nanoparticles were synthesized under various temperature conditions by organic means from the leaf extracts of Syzygiumcumini (Jamun). The efficacy of these metallo nanoparticles was tested against fungi. Thepresence of Silver nanoparticles wasinitiallyanalyzed by color changes of reaction mixture andby Calorimetric readings. The spherical shape of these nanoparticles was confirmed using Scanning Electron Microscopy (SEM).The diameter of synthesized Silver nanoparticles was found within the range of 20-50 nm as confirmed by Transmission Electron Microscopy (TEM). These nanoparticles were assessed for their antifungal potentials against Aspergillusniger and Penicillium sp. by measuring the zone of inhibition. The maximum zone of inhibition was observed against Penicillium sp. using 4 ml extract concentration at 600 C but the activity of these particles was not observed against A. niger.