Magnetite nanoparticles are becoming increasingly important for the development of novel biomedical and nanotechnology applications. What if these magnetite nanoparticles are synthesized with uniform shape, size, and dispersion? This leads to the significance of magnetosomes of magnetotactic bacteria (MTB). MTB are aquatic microorganisms that have the ability to biomineralize membrane-bound iron mineral nanocrystals called magnetosomes. Magnetosomes can be easily functionalized because of the presence of various chemical groups at their surface. To explore the world of magnetosomes, it is important to understand their surface chemistry. The two major components of magnetosomes are the magnetosome membrane (MM) and magnetite mineral. MM consists of lipids and proteins. The MM lipids are divided into three major groups of fatty acids phospholipids, glycolipids, and neutral lipids. The proteins present in MM are designated as “Mam” and “mms” proteins. Magnetosome magnetite crystals have unique properties over synthetic nanoparticles such as narrow size distribution, superior shape control, high purity with limited defects, better T2 reducing effect, and chain-like alignment. The genetic manipulation of biomolecules present in the membrane and the excellent characteristics of magnetite make magnetosomes a better candidate for biomedical applications.