The antibacterial activity of microbially silver nanoparticles was investigated against various pathogenic bacteria of Gram-positive (Staphylococcus aureus) and Gram-negative (Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumoniae and Proteus vulgaris) strains using disc diffusion method. The highest antimicrobial activity was observed against Pseudomonas aeruginosa followed by Staphylococcus aureus and Klebsiella pneumoniae and the least was noticed against Proteus vulgaris and Escherichia coli (Figure 3).