Synthesis and characterization of nanosilver based antimicrobial natural rubber latex foam (NRLF) is described. Silver nanoparticles were synthesized by reducing silver nitrate by tri-sodium citrate in an aqueous medium. UV–Vis spectrophotometer analysis, particle size analysis and transmission electron image analysis proved that the resultant silver nanocolloid was an aqueous dispersion consisting of stable nanometer size silver particles. Antibacterial activities were tested against Gram-positive Staphylococcus aureus and Gram-negative Escherichia coli (E. coli) bacteria, whereas antifungal activities were tested against Aspergilles niger (A. niger). It was found that the resultant NRLF samples inhibit the growth of the these bacteria and fungus in a very strong manner.