Copper nanowire/epoxy terminated poly(dimethylsiloxane) (ETDS) composites were prepared and used as thermal interface materials (TIMs). The surfaces of copper nanowire were coated with SiO2 to enhance their thermal and mechanical properties in the ETDS matrix. The thermal conductivity of CuNW/ETDS composites continuously increased with an increasing loading of CuNW filler. Moreover, at fixed particle loadings, an increased thermal conductivity was observed in surface-modified composites (CuNW@SiO2/ETDS). The effects of SiO2-coated copper nanowire were investigated using thermal conductivity prediction models. The storage modulus graphs illustrated the enhancement achieved by surface treatment of CuNW. In addition, the SiO2-coated copper nanowire composites showed decreased electrical conductivity as compared to the raw copper nanowire composites. Thus, these SiO2-coated copper nanowire/ETDS composites may be used' as thermal interface materials in the electronics industry.