Graphene has attracted much attention to be used as nano-filler in polymer-matrix composites. However, graphene tends to agglomerate when incorporated in a polymer matrix due to strong van der Waals forces between its sheets and thus reduces interfacial interaction between the filler and matrix. Graphene agglomeration can be prevented by functionalization it with a suitable reagent and by utilizing better dispersion techniques. In the present work, graphene oxide (GO), produced from graphite by improved Hummers method followed by sonication in ethanol,were covalently functionalized with 3-aminopropyl triethoxy-silane (APTS) and were dispersed in an epoxy matrix using solution mixing followed by three roll milling. Atomic force microscopy (AFM) images showed that GO had a thickness of ca. 1 nm and the thickness and surface morphology of FGO slightly changed then the former. GO and functionalized graphene oxide (FGO) epoxy-based composites were developed at 0.25 and 1wt. % filler content and their resulting mechanical properties were studied. Fourier transform infrared spectroscopy (FTIR) which confirmed successful functionalization of GO and its covalent bonding with the epoxy resin. The results of the tensile testing showed that strength of composites was enhanced at lower filler content.