There is a growing interest in the use of nanosystems such as nanoalloys, bimetallic nanoparticles, metallic nanoparticles and magnetic nanoparticles in biomedical applications. These applications can be as diverse as hyperthermic treatments; targeted drug delivery; bio-imaging; cell labelling and gene delivery. The use of nanoalloys in these applications has received only limited attention due to the fact that there were many unanswered questions and concerns regarding nanoparticles and nanoalloys such as their stability over time, tendency to agglomerate, chemical activity, ease of oxidation, biocompatibility and cytotoxicity. In this chapter we survey current applications and advances in magnetic nanoparticles used in these biomedical applications so as to understand the materials properties that can pave the way for the use of nanoalloys as a potential alternative or improve solutions that are offered by current materials.