Aluminum/graphene (Al/G) composites with enhanced heat-dissipation and mechanical properties were prepared by the powder metallurgy (P/M) technique. Graphene was first uniformly coated on the surface of micro-sized aluminum (Al) powders by an in-situ reduction reaction of GO and Al. Al/G bulk composites with uniform graphene dispersion in Al matrix were fabricated by the simple conventional P/M technique. Enhancements of 15.4% in thermal conductivity, 9.1% in specific heat capacity, 21.1% in hardness, and 25.6% in compressive strength were achieved with only 0.3 wt% graphene addition into pure Al. Display omitted •Dispersion of graphene in aluminum matrix by in-situ reduction of graphene oxide on aluminum particles.•Alcohol washing was adopted to avoid the hydrolysis reaction of aluminum and guarantee the purity of the composites.•Enhancement of heat-dissipation and mechanical properties by adding graphene into aluminum matix.