Silver-nanoparticle-decorated polypyrrole (PPy) nanotubes (NTs) were fabricated by vapor deposition polymerization (VDP)-mediated hard-template method. Fe/Ag cations were attached on the wall of an AAO template by electrostatic interactions, and pyrrole monomers were polymerized by the reduction of Fe/Ag cations due to chemical oxidation polymerization. The Ag NPs/PPy NTs are applied as antimicrobial agents against Gram-negative Escherichia coli and Gram-positive Staphylococcus aureus. The antimicrobial results show that the antimicrobial performance of Ag NPs/PPy NTs increases with the increasing of the population of Ag NPs loaded on PPy NT. At 30% (wt/wt) Ag NPs/PPy NTs, the minimum inhibitory concentrations (MICs) were 10 and 200 ${mu}g$/mL against Escherichia coli and Staphylococcus aureus, respectively.