Epoxy/silver nanowire (AgNW) nanocomposites are emerging class of materials that provide electrically conductive properties to insulating epoxies by adding AgNWs with a high aspect ratio. However, AgNWs are easy to agglomerate due to their van der Waals attractions, resulting in an obstacle to enhance material properties. Silica nanoparticles (SNPs) known to have good affinity with metallic nanofillers prevent agglomeration of the nanofillers. In this study, the effect of SNPs on the dispersion and electrical properties of epoxy/AgNW nanocomposites was investigated. In the nanocomposites of AgNW 3 vol%, electrical conductivity was sharply increased with the addition of SNPs by 2.63, 3.95, 5.26, and 7.89 vol%. The electrical network of AgNWs could be formed at SNP 3.95 vol%. With the addition of SNP 7.89 vol%, the electrical percolation threshold of epoxy/AgNW nanocomposites was AgNW 1.39 vol% and the electrical conductivity at AgNW 4 vol% was as high as 10 S/m.