We reveal the effects of magnetic substitutional impurities on the density of states (DOS) of a graphene monolayer through the s–f model as well as coherent potential approximation. We show that the magnetic exchange interaction between the itinerant electrons in graphene and magnetic moments leads to ferromagnetic order and spin-splitting band below Curie temperature, which substantially affect the DOS. Furthermore, ferromagnetic graphene exhibits metallic behavior owing to the strong s–f exchange leading to the appearance of a sharp quasiparticle peak near the Fermi level. These phenomena, along with the gaps appearing in the DOS open prospects for new applications in pintronics and optics.