Importance of magnetic nanoparticles in daily life including biomedical applications in near future cannot be overlooked. This review focuses on the properties of magnetic nanoparticles (MNPs), various approaches for their synthesis, and their biomedical applications. First part of this review focuses on the classes, physical properties, and characteristics of MNPs. The second part sheds light on strategies developed for the synthesis of MNPs, with special attention given to biological, physical, and chemical approaches as well as recent modifications in the preparation of monodispersed samples. Furthermore, this review deals with the biomedical applications of MNPs, which includes applications in targeted drug delivery, diagnostics, gene therapy, hyperthermia and advantages in the field of medicine.