Graphene research has become an emerging frontier in materials science due to its exceptional electrical and thermal conductivity, high mechanical features, electron mobility, and its high specific surface area. Excellent characteristics of graphene deliver it to developed and applied in various applications. A combination of iron oxides nanoparticles (IONPs) and graphene produces a magnetic graphene nanocomposite. The received structure not only has the characteristics features of magnetization and a large specific surface area, but also it can improve the other remarkable disadvantages in the singular nanomaterials as the aggregation of IONPs and the low recovery of the graphene from the dispersion solvent. The magnetic graphene nanocomposite can be fabricated through various designs techniques such as natural blending of graphene derivative and magnetic nanoparticles, in-situ synthesis of the magnetic nanomaterials on graphene derivative, and covalent functionalization. The magnetic graphene nanocomposite can be potentially used in several biological and environmental applications such as MRI, drug delivery systems, hyperthermia, combined therapy, immobilization, and the adsorption of heavy metal, radioactive metal ions, and pesticides. In this article, the preparation procedures, properties, structure characteristic features, biocompatibility, and the biological-environmental applications, will be highlighted. Furthermore, challenges, visions, and prospects on the future trends have been introduced as concluding comments.