We report a facile and effective technique for the large-scale production of nano-sized graphene sheets via subjecting the microcrystalline graphite to ball milling. The products consist of single- or few-layer (≤5 layers) graphene with lateral dimensions concentrated in the range of 100–200 nm. It displays a high intensity of photoluminescence at a wavelength of 339 nm and graphene dispersions at concentrations up to 1.22 mg ml⁻¹.