Graphene sheets (GNPs) were functionalized with gold nanoparticles via a spontaneous deposition of gold particles on its surface occurred by chemical reduction of (Au3+). Even after only 1 min of reaction, the reduction of Au3+ into metallic Au-0, takes place in evidencing the rapid and spontaneous character of the reduction. The particles, after only 3 min of deposition, have very small diameters, with average centred at 17 nm. The Au-GNP nanofillers were dispersed into UV-curable epoxy resin. Conductivity of the epoxy crosslinked samples containing Au-GNP nanofiller were compared to the values obtained for epoxy nanocomposite containing the same amount of bare graphene; the electrical conductivity was significantly increased by the addition of Au-GNP nanofiller, of about four orders of magnitude. This could be attributed to a charge transfer mechanism, which is strongly enhanced by the presence of gold NPs.