Reduced graphene oxide/silver (rGO/Ag) nanoparticles (RGANs) were prepared in an in situ facile way. The RGANs microstructure was characterized by field-emission scanning electron microscopy, transmission electron microscopy, x-ray diffraction, and Raman spectroscopy, respectively. The tribological performance of liquid paraffin (LP) containing oleic acid-modified rGO/Ag nanoparticles (ORGANs) demonstrated that the LP-ORGANs showed excellent friction-reducing and antiwear properties than pure LP. The investigation revealed that the synergetic effect and the deposition of tribo-film containing elements of C, N, O, Fe, and Ag improved their tribological properties. The permeation of Ag ions into the graphene oxide (GO) interlayers and the growth of Ag nanoparticles possibly contribute to the small Van der Waals forces of rGO nanosheets and result in excellent friction reduction and antiwear actions.