In this study, we comparison of the antimicrobial activity on the nanosilver shapes; Ag-nanoplates (Ag-NPIs), Ag-nanorods (Ag-NRds) and Ag-nanoparticles (Ag-NPs). Nanosilver shapes were prepared with a stabilizer, such as poly (N-vinyl-2-pyrrolidone) (PVP). Antimicrobial effect of nanosilver shapes for Staphylococcus aureus (S. aureus) and Escherichia coil (E. coli) was investigated using disc diffusion and minimum inhibitory concentration (MIC) methods. The growth of Gram-positive (S. aureus) and Gram-negative (E. coil) bacteria were inhibited by nanosilver shapes. With BET technique, it was found that surface area of nanosilver shapes are key factor for controlling antimicrobial activity inside of the S. aureus and E. coil bacteria. Anti-bacterial activity of nanosilver shapes was found to be dependent on the shape and size of silver particles. Also, the Ag-NPIs did show the best surface area and antimicrobial activity for the test organisms. The scanning electron microscopy (SEM), indicated that, the most strains of S. aureus and E. coil were damaged and extensively disappeared by addition of Ag-NPIs. (C) 2010 The Society of Powder Technology Japan. Published by Elsevier B.V. and The Society of Powder Technology Japan. All rights reserved.