The objective of this work is to improve the properties of natural rubber composites (NRC) that were frequently used in medical and health supplies, using nanosilver additions. Silver nanocolloids were biosynthesized with an aqueous medium of aloe leaf extract (ALE) as capping agent, and then were filled in natural rubber matrix to prepare nanosilver-based NRC. UV–vis spectrophotometer, X-ray diffraction, and transmission electron microscopic analyses proved that the particle size of resultant silver was about 20 nm. The antibacterial activities against Staphylococcus aureus and Escherichia coli bacteria of NRC were dependable on the silver nanoparticles content and the treating methods on ALE, which was used in synthesizing silver nanocolloids. The morphology and thermal stability effect of nanosilver on NRC were determined with scanning electron microscopic and thermogravimetric analysis, respectively.