Graphene and its derivatives are regarded as promising reinforcing agents in the metal matrix because of their excellent intrinsic mechanical properties. Considering the availability of graphene with various types, defect states and intrinsic properties, there exists a large space in tailoring the mechanical behavior of graphene reinforced metal matrix composites. This article reviews the recent developments on the processing and structure-property correlations of these composites. Particular emphasis is given to the structure and properties of the graphene/metal interfaces, as the external mechanical load is transferred between nanocarbon and the metal matrix across their interfaces. Moreover, in addition to the intuitive load-bearing effect of graphene, a copious interplay between graphene and dislocations in the metal matrix has been found, which alters the deformation mechanism and leads to additional strengthening. To meet the requirements of structural applications, scalable fabrication routes for the graphene/metal composites should be developed and the study on the mechanical behavior under real service conditions is to be carried out.