The use of microbes in the synthesis of silver nanoparticles emerges as a cost effective and eco-friendly approach. In the present study, the biosynthesis of silver nanoparticles using Aspergillus flavus and its antibacterial properties were evaluated. The biologically synthesised silver particles are characterized by UV-Vis spectrophotometry. The silver nanoparticles showed the absorbance peak at 409nm in the UV-spectrophotometer. These silver nanoparticles were further characterized by Fourier Transform Infrared (FTIR) spectroscopy, Atomic force microscopy (AFM). The AFM study of silver nanoparticles showed the shape and size of individual nanoparticles as well as it focused a few aggregates having the size in the  range of 55-70nm.The bactericidal action of biologically synthesised silver nanoparticles against gram positive and negative bacteria was found with high potentiality. When Ofloxacin (5 mcg ml^-1) and Moxifloxacin (5 mcg ml^-1) were combined with silver nanoparticles (20mg/ml^-1), it resulted in greater bactericidal efficiency on selected bacterial pathogens. The results confirmed that the solutions with more silver nanoparticles had better antimicrobial effects which would be the novel remedy substituent in the place of higher doses of antibiotics.