Despite the over spatial separation and the ability to determine soft tissues, insufficient contrast is the shortcoming of magnetic resonance imaging (MRI) that could be circumvented by the use of contrast agents. The use of MRI contrast agents are widely applied to enhance the vision of internal body structures. Nano-sized contrast materials have unique application advantages compared to other contrast agents due to their size and shape. However, for contrast agents such as bare iron (II, III) oxide (Fe3O4) magnetic nanoparticles (NPs), aggregation and accumulation are the main shortcomings. Thus, surface modifications are necessary for their use in biopharmaceutical applications. Gold, Au, nanoparticles are of big interesting for use in biomedical purposes due to their chemical stability and oxidation resistance. In this study, we synthesized magnetic Fe3O4–Au hybrid NPs with a facile method and coated them with bovine serum albumin (BSA) to increase their chemical stability and biocompatibility. Afterwards, the hybrid nanosystem was characterized by some methods, and their potential to increase MRI contrast was investigated by the phantom MRI experiments. Our data showed that the signal intensity on MR images was significantly reduced, thus confirming the contrast ability of the formulated Fe3O4–Au-BSA NPs.