Recently, graphene-based materials have attracted much interest due to their remarkable mechanical, thermal, electrical and barrier properties ensuring promising applications such as flexible electronics, energy storage devices and nanocomposites. From an industrial application point of view, the best method for large scale production of graphene is based on the oxidation of graphite leading to graphite oxide (GO), which can subsequently be functionalized, followed by its chemical reduction to restore electrical conductivity. Herein, the preparation of polyisoprene/graphite oxide composites was accomplished through the use of polyisoprene-grafted GO. First, the hydrolysis-condensation reaction of acryloxypropyl trimethoxysilane (APTMS) or allyltrimethoxysilane onto GO led to the derivatization of both the edge carboxyl and surface hydroxyl functional groups. Then, the dangling vinyl groups of APTMS or allyltrimethoxysilane were used for in-situ polymerization of isoprene. The modified nanofillers were characterized by thermogravimetric analysis, infrared spectroscopy, differential scanning calorimetry and solid-state nuclear magnetic resonance. Then, the polyisoprene-grafted graphene oxide platelets were dispersed in a polyisoprene matrix at various contents and the corresponding composites were studied through rheological measurements and electron microscopy observations.