While planar graphene has revolutionized science and engineering in many different areas, one of its close relatives, vertical graphene (VG), also known as carbon nanowalls, has not been investigated as extensively. Compared to planar graphene that is grown parallel to the substrate, VG can grow almost vertically on a wide variety of substrates. In this study, we report the fabrication and characterization of VG-based nanocomposite thin films, where the graphene sheets are uniformly distributed in the host polymer. A novel fabrication method was developed and the properties of the fabricated nanocomposites were characterized. The results showed that in our method graphene sheets are much more uniformly dispersed and common issues in graphene nanocomposites, such as agglomeration and breaking of the sheets during dispersion, are avoided. The increase in the Young’s modulus and tensile strength of the fabricated nanocomposites is much higher than that of the samples fabricated using the traditional methods of randomly dispersing graphene using a sonicator or high-speed stirrer.